Trees and Their Economic Importance

Abstract

The biological and logical meaning of trees, which are one of the important woody plants of our ecosystem, are reviewed in
this article. Trees are mostly used for timber purposes, but in the present article the utility of trees with respect to their
importance in restoring, reclaiming and rejuvenating denuded and disturbed soils, their ecological, ecodevelopmental and environmental
use, and their educational and recreational value in gardening, landscaping and bioesthetic planning is described. In addition,
the importance of trees is discussed with reference to their value as a source of sustenance: food, sugars, starches, spices
and condiments, beverages, fumitories, masticatories and narcotics, medicines, essential oils, fatty oils and vegetable fats,
waxes, soap substitutes, vegetable ivory, fodder, fuel, bioenergy or biofuel, fertilizers, fiber, pulp and paper, tannins,
dyes, rubber and other latex products, gums, resins and cork. Lastly, the food plants of mulberry and non-mulberry silkworms,
which feed on the leaves of many forest trees, are mentioned.

Full text

TREES AND THEIR ECONOMIC IMPORTANCE 321
Issued 07 April 2004
© 2004 The New York Botanical Garden
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321
The Botanical Review 69(4): 321–376
Trees and Their Economic Importance
M. K. SETH
Department of Bio-Sciences
Himachal Pradesh University
Shimla 171 005, H.P., India
I. Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
II. Introduction and Classification of Trees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
III. The Economic Importance of Trees . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
A. Trees as a Source of Timber . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
B. Trees in the Restoration, Reclamation and Rejuvenation of Denuded and
Disturbed Soils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
C. Ecological, Ecodevelopmental and Environment Uses of Trees . . . . . . . . . . . . . 325
1. Natural Purifiers of the Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
2. Environment Screens . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
3. The Physical Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
4. Wildlife. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
5. Urban and Rural Afforestation Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
6. Road Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
7. Protection of Road Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326
D. The Educational and Recreational Value of Trees . . . . . . . . . . . . . . . . . . . . . . . . 326
1. Shade and Shelter (or Avenue Trees) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327
2. Ornamental Flowering Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
3. Ornamental Foliage Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328
4. Ornamental Fragrance Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
5. Ornamental Fruiting Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
6. Ornamental Hedges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329
7. Live Screens and Fences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
8. Sculpture and Topiary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
9. Education . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
10. Landscaping and Bioaesthetic Planning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
11. Veneration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
12. Art and Culture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331
E. Trees as a Source of Sustenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
1. Food . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
2. Sugars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332
3. Starches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
4. Spices and Condiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
5. Nonalcoholic Beverages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337
6. Fumitories, Masticatories and Narcotics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
7. Medicines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339
8. Essential Oils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339

322 THE BOTANICAL REVIEW
9. Fatty Oils and Vegetable Fats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
10. Waxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 342
11. Soap Substitutes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
12. Vegetable Ivory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
13. Fodder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
14. Fuel, Bioenergy or Biofuel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349
15. Fertilizers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
16. Fibers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
17. Pulp and Paper . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351
18. Tannins. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
19. Dyes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
20. Rubber and Other Latex Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352
21. Gums . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
22. Resins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 357
23. Cork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370
24. Food for Silkworms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371
IV. Conclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
V. Literature Cited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375
I. Abstract
The biological and logical meaning of trees, which are one of the important woody plants of
our ecosystem, are reviewed in this article. Trees are mostly used for timber purposes, but in the
present article the utility of trees with respect to their importance in restoring, reclaiming and
r
ejuvenating denuded and disturbed soils, their ecological, ecodevelopmental and environmental
use, and their educational and recreational value in gardening, landscaping and bioesthetic plan-
ning is described. In addition, the importance of trees is discussed with reference to their value as
a source of sustenance: food, sugars, starches, spices and condiments, beverages, fumitories, mas-
ticatories and narcotics, medicines, essential oils, fatty oils and vegetable fats, waxes, soap substi-
tutes, vegetable ivory, fodder, fuel, bioenergy or biofuel, fertilizers, fiber, pulp and paper, tannins,
dyes, rubber and other latex products, gums, resins and cork. Lastly, the food plants of mulberry
and non-mulberry silkworms, which feed on the leaves of many forest trees, are mentioned.
II. Introduction and Classification of Trees
Trees are important to humankind not only economically, environmentally and industrially
but also spiritually, historically and aesthetically, for they sustain human life through direct and
indirect gains by providing a wide range of products for survival and prosperity. However, it is
not always easy to define “tree.” A tree is a large, long-lived (i.e., perennial) woody plant that
attains a height of at least 6 m (20 ft) at maturity in a given locality and usually—but not
always—has a single main self-supporting stem called a “trunk” or a “bole,” which gives off
spreading branches, twigs and foliage to make a crown (Venkatesh, 1976; Panshin & de Zeeuw,
1980; Hawkins, 1986). Since the diameter at breast height (dbh) of trees is determined interna-
tionally at 1.35 m (4.5 ft) above the ground, a tree must be unbranched—i.e., with a single
trunk—at least up to 1.5 m (5 ft) from the ground. But this definition does not cover the
following (Venkatesh, 1976), which are also considered trees:
•Palms are typically unbranched trees with only one trunk (columnar stem), called the
“caudex,” which ends in a crown of large leaves.
•Bamboos are trees without a main trunk but with a cluster of culms arising from the
underground rhizome. These culms are unbranched, with distinct nodes and internodes
that give them a jointed appearance.

TREES AND THEIR ECONOMIC IMPORTANCE 323
•The banana tree (plant) has only a thick false stem (pseudostem), which is not woody but
made up of a central core of soft tissues concealed by the fibrous and sheathing bases of
large leaves. Strictly speaking, the banana plant is a giant herb.
•Tree ferns like Cyathaea and Alsophila have erect rhizomes with generally unbranched
trunks, topped by a crown of graceful, feathery fronds that form a rosette at the apex.
•Bonsai—i.e., tailored or humanmade miniature or dwarfed living trees that have been
prevented from reaching their normal size—are grown in pots and kept in greenhouses,
drawing rooms, etc. This technique was first perfected by the Japanese.
In addition to the above definitions, the scientific distinction between trees, shrubs, lianas
and undershrubs or semishrubs is not always clear. For example, many species of trees—e.g.
Rhododendron spp., which are large under normal conditions—become shrubs when growing
near their altitudinal and latitudinal limits. Woody plants in which several branches arise from
near the base, giving the plant a bushy appearance, are called “shrubs.” Likewise, certain spe-
cies of figs (Ficus spp.) begin their life as woody climbers called “lianas” but eventually end up
as trees; i.e., they become arborescent. Similarly, Grewia scabrophylla at times is an under-
shrub, when exposed to annual fires; in other places, however, it grows into a tall shrub (Panshin
& de Zeeuw, 1980). The science dealing with the study of woody plants—i.e., trees and shrubs—
is called “dendrology.”
Trees can be classified in several ways: Depending upon their utility or end products, they
may be called “avenue,” “ornamental,” “shade bearing,” “fragrant,” “fruit bearing,” “medici-
nal” or “drug yielding,” “timber yielding,” “fodder yielding,” “nitrogen fixing,” “venerated,”
“fuel yielding,” “fiber yielding,” “multipurpose trees,” etc. Those trees that remain green in
their dormant season due to persistence of leaves are called “evergreen trees.” In such trees all
the leaves do not fall off simultaneously, and the plants are never leafless. Those trees in which
all the leaves of a plant fall at the end of one growing season one by one or simultaneously,
leaving the plant leafless in the dormant season, are called “deciduous trees.” All cone-being
trees are called “conifers” or “coniferous trees,” and all trees that are not cone bearing but are
flower bearing are called “flowering trees” or “broad-leaved trees.” Whereas conifers have
needle-shaped leaves, flowering trees have broad or flattened leaves.
A conifer usually has a conical appearance and has an excurrent stem; i.e., its main stem is
thickest at the base and gradually tapers toward the apex, with lateral branches in an acropetal
succession. A flowering tree usually has a dome-shaped appearance and a deliquescent or de-
current stem in which the main trunk divides at some distance from the ground into several
branches, which branch again and again, making the trunk appear to deliquese or melt away.
Ornamental trees that have showy flowers are called “ornamental flowering trees,” and
those with beautiful foliage and inconspicuous flowers are called “ornamental foliage trees.”
The former are usually deciduous; the latter, evergreen.
Those trees in which seeds are borne naked are called “gymnosperms” (from the Greek
gymnos [naked] and sperma [seed]), and those trees in which seeds are enclosed within an
ovary/fruit wall are called “angiosperms” (from the Greek angeon [vesicle] and sperma [seed]).
The angiospermic trees are further classified into dicotyledonous or dicot trees, if they have
two cotyledons in their seeds, and monocotyledonous or monocot trees, if they have only one
cotyledon in their seeds. Both gymnosperms and angiosperms are sometimes placed under one
division, called “spermatophyta,” “siphonagama” or “phanerogams.” “Spermatophytes” (from
the Greek sperma [seed] and phyton [plant]) are those plants that are seed bearing. “Siphona-
gama” (from the Greek siphon [tube] and gamous [marriage]) are those plants in which fertili-
zation occurs by means of a pollen tube. “Phanerogamous” (from the Greek phaneros [open]
and gamous [marriage]) are those plants in which reproduction is not concealed or hidden but

324 THE BOTANICAL REVIEW
open; i.e., they bear flowers and produce seeds. Trees belonging to gymnosperms and an-
giosperms not only constitute the dominant component of any vegetation but also add to the
biodiversity or biological diversity of any particular region.
III. The Economic Importance of Trees
Trees represent one of the important components of each and every terrestrial ecosystem
and are a part of nature’s precious gifts. Some are deciduous; others are evergreen. Some have
beautiful flowers; others have beautiful fruits or foliage. Some are scented; others are ugly but
economically very important. The welfare of humankind is affected not only by their density
and diversity but also by their direct and indirect values, which are beyond estimation. In fact,
each letter of the plural word “TREES” has a logical meaning (Seth, 2002):
TTimber, the first and the foremost use of trees
RRestoration, reclamation and rejuvenation of denuded and disturbed soils
by using trees to control soil erosion and desertification, protect water-
sheds, improve soil nutrient status (by growing nitrogen-fixing trees) and
retain moisture in the soil
EEcological, ecodevelopmental and environmental use of trees for effective
and efficient purification of the environment because trees act as oxygen
banks and eliminate air pollutants; for abating or moderating temperature,
noise and wind by planting trees as environmental screens, thus affecting
the microclimate; for harboring wildlife; for maintaining biodiversity; and
for conserving energy
EEducational and recreational value in gardening, landscaping, bioesthetic
planning, art, culture and religion
SSource of sustenance; i.e., food, fuel, fodder, fertilizer, fiber, medicine,
tannin, dyes, oils, etc.
A. TREES AS A SOURCE OF TIMBER
Trees are woody perennial plants, i.e. they are capable of producing wood through the
meristematic activity of the vascular cambium. The latter gives rise to secondary xylem
(nontechnically called “wood”) toward its inner side and to secondary phloem (nontechnically
called “bark”) toward its outer side. Wood produced by cycads is called “manoxylic.” It is not
compact—i.e., it is loose, not dense—with wide rays, pith and cortex and thus useless commer-
cially. Wood produced by conifers, taxads, Ginkgo biloba and dicots is called “pycnoxylic.” It
is compact and dense, with narrow rays, pith and cortex and hence commercially very useful.
The commercially useful woods are called “timbers,” and timber that is used for building pur-
poses is called “lumber.” Tectona grandis (teak) and Cedrus deodara (deodar) are, respec-
tively, considered the best angiospermic and gymnospermic timbers in the world.
Woods obtained from timber trees are used for construction and other miscellaneous pur-
poses like agricultural implements, boat and ship building, carts and carriages, carving and
turnery, cooperage (barrel making), electric poles, engraving and printing blocks, furniture and
cabinet work, matches and match boxes, mathematical instruments, musical instruments, pack-
ing cases and boxes, pencil and pen holders, picture framing, railway carriage and wagon
building, railway sleepers, rifle parts, shoe heels and boot lasts, shuttles, sports goods, tea
chests, toys, etc. For examples of these one may consult Anonymous (1970–1972, 1983) and
Trotter (1940, 1944).

TREES AND THEIR ECONOMIC IMPORTANCE 325
B. TREES IN THE RESTORATION, RECLAMATION AND REJUVENATION OF
DENUDED AND DISTURBED SOILS
Planting trees on denuded and waste land, along roads, railway tracks, deserted areas, wa-
tersheds, etc. protects soil from erosion by wind or water by firmly binding it with roots and by
diverting runoff during rains. The sides of the roads, railway tracks and watersheds can thus be
protected. Desertification can likewise be controlled by planting trees. The trees also retain
moisture in the soil, and if nitrogen-fixing trees are grown, the nutrient status of the soil can be
enriched tremendously.
The sap of Cassia fistula (amaltas) leaves contains certain chemicals that have a purgative
action on the digestive organs of grazing animals like goats, cows and buffalo, and thus amaltas
is well suited for planting on wastelands. Wild fruit trees like Zizyphus jujuba (ber) and Morus
alba (toot) can also be propagated on wastelands in and around villages.
C. ECOLOGICAL, ECODEVELOPMENTAL AND ENVIRONMENT USES OF TREES
1. Natural Purifiers of the Environment
Plants, including shrubs and trees, act as biological filters by helping cleanse the environment.
They are the best natural purifiers of environment pollution; i.e., they improve the quality of the air
we breathe. First, they act as the oxygen banks on this planet. They play an important role in
maintaining the oxygen cycle, which is essential for the survival of all forms of life. Second, they
may help reduce pollution. Leaves can absorb gaseous pollutants on their surfaces, especially if
their surfaces are waxy, spiny or hairy. In addition, stems, branches and twigs can intercept particu-
lates. Third, they reduce oxides of carbon in the air, can also fix atmospheric nitrogen, disintegrate
waste and act as sinks of pollution or pollutant scavenges by absorbing and metabolizing toxic
gases and heavy metals (Chakraverty & Jain, 1984).
Different species as well as individuals within a species can vary in their tolerance to pollut-
ants. High concentrations of pollutants can damage and even kill many tree species. Trees that
are particularly sensitive could be used as early warnings of high pollution levels.
2. Environmental Screens
When properly grown in urban and rural areas, trees act as wind barriers by decreasing the
force of the wind and reducing the level of noise from highways and other sources. Even
individual trees, if strategically planted around a house, can provide relief from noise and
annoying lights at night. Trees thus reduce stress on human beings. Ecologically they act as
wind breaks and shelter belts, thus providing protection against soil erosion and a defense
against encroachment by seas, floods and deserts.
3. The Physical Environment
Trees help to reduce temperature by providing shade and by intercepting, absorbing and
reflecting solar radiation, especially in warmer places, where there is year-round warmth and
sunshine (Schubert, 1979). Trees also function as natural air conditioners by evaporating water
from their leaves through the process of transpiration. A single large, well-watered city tree can
transpire about 380 liters (100 gallons) of water in one day, thus producing the cooling effect of
five average room air conditioners running 20 hours a day (Schubert, 1979). Trees thus im-
prove the microclimate; i.e., they help control and stabilize the climate of the region and of the
world as a whole. A single tree standing alone may not affect the overall surrounding much, but

326 THE BOTANICAL REVIEW
a belt or groups of trees or many trees scattered throughout the neighborhood can be quite
effective (Schubert, 1979).
4. Wildlife
Trees, both native and ornamental, harbor wildlife. They directly feed and house the major-
ity of world’s creatures and animals like insects, birds, small mammals and reptiles, which we
need in order to live. Thus they play a major role as one of the important components of natural
and humanmade biodiversity.
5. Urban and Rural Afforestation Programs
Large-scale urbanization and industrialization have led to the development of severely eroded,
barren and denuded areas, rocks, cliffs, etc. on which direct plantation of trees is difficult. In
such cases shrubs act as the primary colonizers of denuded areas. The successful growths of
shrubs create favorable conditions for tree growth by way of retaining moisture, increasing soil
nutrient status and sheltering the trees from frost, wind and other biotic interferences through
the process of secondary succession. The whole forest-management program can thus bring
not only greenery to the Himalayas and other urban and rural regions of India but also stability
to the environment by restoring the ecological balance (Maithani et al., 1991).
6. Road Safety
The presence of shrubs and trees along roadsides makes their edges and curves conspicu-
ous, thus making a natural guide for safe driving, and for this purpose the lower portions of
their stems are usually painted white (Chakraverty & Jain, 1984).
7. Protection of Road Surfaces
The semimelting of tar or bitumen in summers, cracking of road surfaces during hot weather
and mechanical damage to road surfaces by heavy downpours and hailstorms can largely be
prevented by growing roadside trees with thick crowns (Chakraverty & Jain, 1984).
D. THE EDUCATIONAL AND RECREATIONAL VALUE OF TREES
Increased urbanization and industrialization have resulted in isolating humans from nature.
Trees can help make urban areas green, livable and beautiful. Trees with colorful flowers or
foliage add extra attractiveness. They are the dominant elements of gardens and contribute
substantially to the garden atmosphere.
According to Kohli (1996), the comfortable urban life needs better avenue trees and shrubs,
because:
•An agricultural component is not feasible;
•Comfortable temperatures and microclimates for residents are needed;
•Pollutants that pose major problems are to be removed;
•Cool shade is needed in summer; and
•Dense populations need vegetation for gaseous exchange.
Trees are thus a source of pleasure and recreation when they are planted along roads and
railway tracks and in botanical gardens, arboreta, city parks, squares, home gardens, public
places, industrial areas, etc. The cultivation of trees for their aesthetic or recreational value is

TREES AND THEIR ECONOMIC IMPORTANCE 327
known as “arboriculture.” In an ornamental garden they are usually planted either as specimen
trees or in groups. The educational and recreational value of trees can be studied under the
following headings:
1. Shade and Shelter (or Avenue Trees)
The concept of avenue planting is as old as the vedic period. It was during the period of
Ashoka (260 B.C.) and later during the reign of Kanishka (A.D. 78–101) and the Mughals,
however, that the foundations of proper roadside avenues were laid.
When properly grown, the tall, fast-growing and majestic trees with thick foliage along
roadsides provide not only shade for pedestrians and travelers but also shelter for stray animals
from scorching heat, wind, rain, etc. Species selected for such purposes should not be thorny or
prickly (Chakraverty & Jain, 1984).
The other important factors for selection of roadside trees, according to Chakraverty and
Jain (1984) and Randhawa (1961, 1965–1983), are:
•The trees should be branchless up to 3–4 m above the soil surface so that vehicles can
pass easily, particularly on narrow roads.
•On national highways or on very wide roads, two to three deep rows of large trees
spaced 5–6 m apart should be planted. These trees should have good, dense crowns so
they can provide adequate shade and protection from rain, sun and hail.
•Dwarf trees or medium-sized-to-large shrubs, preferably ever blooming in nature, should
be selected for boulevards and road medians.
•The trees should not have spreading crowns that might obstruct the growth of trees in
the opposite row.
•Trees on the two sides of the road should not be opposite each other; they should be
planted alternately.
•Fuel-wood species and fodder species should not be chosen for the roadsides, because
they are likely to be lopped, pruned and chopped by the neighboring inhabitants, thus
destroying the landscaping and giving the avenue a shabby appearance.
•The root system of the trees should be neither very spreading nor very shallow. Trees
with very robust and spreading root systems damage the masonry work of roads, foot
paths and adjacent buildings. On the other hand, trees with shallow root system, like
Millingtonia hortensis (mahanim), topple over in storms and obstruct traffic. Thus trees
with deep root systems should be selected.
•Trees like Ficus benghalensis (bat or barghad) have hanging aerial roots, which would
obstruct traffic and pedestrians, so they should not be selected.
•Soft-wooded and brittle trees like Albizia lebbek, Cassia siamea, Eucalyptus spp., Eugenia
jambolana, Ficus glomerata, Millingtonia hortensis and Sygyzium cumini should not be
planted along roadsides, for they tend to break in storms and block traffic.
•During summers and rainstorms, protection from sun and rain are most needed, so trees
that shed their leaves during these periods should not be planted. Moreover, fallen leaves
in the rainy season make the road slippery and block the drainage system.
•Various species of Acacia, Zizyphus, etc., which are prickly or thorny, should not be
planted because the fallen prickles or thorns cause trouble for pedestrians, animals and
people and may also damage the tires of cycles and vehicles.
•The trees should have the ability to withstand winter lopping, when little shade is re-
quired. These loppings can be utilized as fuel wood (Singhal & Khanna, 1991).
•Too many species should not be mixed within short distances, particularly on roads
away from cities and towns.

328 THE BOTANICAL REVIEW
Randhawa (1965–1983) recommended avenue trees for planting purposes: as foliage trees
for outer avenues for town roads, Albizia procera (safed siris), Anthocephalus cadamba (kadam),
Averrhoea carambola (kamrak), Bassia latifolia (mahua), Callistemon lanceolatum (lal botal
brush), Dalbergia sissoo (shisham), Eugenia operculata, Mangifera indica (mango), Melia
azedarach (drek), Pithecolobium saman (rain tree), Platanus orientalis (chinar), Polyalthia
longifolia (ashoka), Putranjiva roxburghii, Sterculia alata, Tamarindus indica (imli), etc; as
flowering trees for inner avenues for town roads, Bauhinia purpurea (gulabi kachnar),
B. variegata (kachnar), Cassia fistula (amaltas), Colvillea racemosa (kilbili), Gliricidia maculata
(madre tree), Grevillea robusta, Jacaranda mimosaefolia (nili-gul-mohur), Lagerstroemia flos-
reginae (jarul, crepe flower), L. thorelli (barri sanwani), Peltophorum ferrugineum (ivalvagai),
Poinciana regia (gul mohur), Spathodea nilotica (fountain tree), etc.
2. Ornamental Flowering Plants
Ornamental trees that have showy flowers are called “ornamental flowering trees.” India
has the largest number of flowering trees in the world, indigenous as well as exotic, that can be
utilized for beautifying towns. Many trees bloom at a particular season and appear more effec-
tive when planted in groups.
In small and medium-sized gardens, ornamental trees should be planted only in the bound-
aries as foundation planting. An “arboretum” is a garden of trees. While planting a tree, beauty
and utility should be combined deftly. The best time for planting trees is during the rainy
season.
Dwarf ornamental flowering trees suitable for small compounds are Acacia auriculiformis,
Alangium lamarckii, Bauhinia purpurea, B. variegata, Brownea ariza, B. coccinea, Butea
frondosa, Cassia fistula, C. javanica, C. marginata, Cochlospermum gossypium, Cordia
sebestena, Crataeva religiosa, Erythrina blakei, E. cristagalli, Gliricidia maculata, Guaicum
officinale, Holarrhena antidysentrica, Jacaranda mimosaefolia, Kleinhovia hospita, Lager-
stroemia thorelli, Mesua ferrea, Milletia auriculata, Plumeria alba, P. rubra, Pongamia glabra,
Saraca indica, Solanum wrightii, Spathodea nilotica, Sterculia colorata, Tecomella undulata,
Thespesia populnea, etc. (Cowen, 1950; Randhawa, 1965–1983).
For large compounds, some examples of beautiful flowering trees are Anthocephalus indicus,
Bombax malabaricum, Cassia grandis, C. nodosa, Chorisia speciosa, Colvillea racemosa,
Lagerstroemia flos-reginae, Millingtonia hortensis, Peltophorum ferrugineum, Poinciana re-
gia and Sterculia colorata (Cowen, 1950; Randhawa, 1965–1983).
Trivedi (1983, 1987, 1996) recommended the following small trees for the hills: Acacia
alata (with bright yellow flowers), A. dealbata (with light yellow flowers), Bauhinia variegata
(with rose, purple and white flowers), Magnolia grandiflora (with white flowers), Prunus
serrulata (with pink flowers), Rhododendendron arboreum (with crimson flowers) and R. cam-
panulatum (with magenta flowers). Trivedi also recommends a few trees for cultivation on the
plains.
3. Ornamental Foliage Plants
Ornamental trees with beautiful foliage but inconspicuous flowers are called “ornamental
foliage trees.” Common examples are palms, evergreen conifers, Acacia auriculiformis, Averrhoa
carambola, Callistemon lanceolatum, Citharexylum subserratum, Diospyros embryopteris,
Eucalyptus spp., Ficus infectoria, F. retusa, Kigelia pinnata, Phyllanthus emblica, Polyalthia
longifolia, Putranjiva roxburghii, Tamarindus indica and Terminalia arjuna (Randhawa, 1961,
1965–1983).

TREES AND THEIR ECONOMIC IMPORTANCE 329
Evergreen shrubs and trees provide a structure for the garden during winter months. With-
out them the garden will look bleak and dull, when the foliage of most herbaceous perennials
disappears, leaving only bare stems and branches.
In temperate regions conifers constitute the most important and showy group of plants.
Many varieties show symmetrical growth and are frequently used in formal gardens. They keep
their ornamental effect even in winter, when most broad-leaved trees shed their leaves. Com-
mon examples of foliage trees in the hills are the species of Araucaria, Cryptomeria and
Cupressus (Trivedi, 1983, 1987, 1996).
4. Ornamental Fragrance Plants
Many trees combine beauty with fragrance. Some trees that are commonly cultivated for
scent or fragrance are Acacia podalyriaefolia, Anthocephalus indicus (kadam), Biota orientalis,
Citrus aurantifolium (lime), C. japonica, C. limon (lemon), Cymphomandra betacea, Garde-
nia lucida, G. latifolia, G. resinifera (dekamali), Galphimia gracilis, Grewia asiatica, Luculia
gratissima, Magnolia grandiflora (bara champa), Michelia champaca (champa or champak),
Mimusops elengi (maulsari), Nyctanthes arbor-tristis (harsinghar), Plumeria tuberculata, Rhodo-
dendron formosum and Sambucus nigra (Randhawa, 1961). In home gardens these can be
planted opposite windows and doors of bedrooms, so that one can enjoy their fragrance in the
evening, particularly in summer months (Randhawa, 1961, 1965–1983; Trivedi, 1990).
Some examples of fragrant ornamental trees for large compounds are Dillenia indica,
Mimusops elengi and Pterospermum acerifolium (Randhawa, 1965–1983).
Trees with snow-white, fragrant flowers against the background of dark green foliage are
very delightful for moonlit gardens. Some common examples in this category are Bauhinia
alba, Citharexylum subserratum, Crataeva religiosa, Delonix regia, Dillenia indica, Erythrina
variegata, Gardenia resinifera, Gliricidia alba, Holarrhena antidysentrica, Lagerstromia in-
dica (white), Millingtonia hortensis, Mimusops elengi, M. hexandra, Plumeria acutifolia, P. alba,
Prunus domestica and Wrightia tinctoria (Randhawa, 1961).
5. Ornamental Fruiting Plants
Trees commonly grown for their beautiful, attractive and colorful fruits are Citrus micro-
carpea, Hazara orange and other Citrus spp., papaya (Carica papaya), peach (Prunus persica),
pineapple (Ananas comosus), tree tomato (Cymphomandra betacea), banana (Musa
paradisiaca), strawberry tree (Arbutus unedo), quince (Cydonia oblonga), loquat (Eriobotrya
japonica), common spindle tree (Euonymus europeaus), gean (Prunus avium), pomegranate
(Punica granatum) and jujube (Zizyphus jujuba) (Lunardi, 1987; Trivedi, 1983, 1987, 1996).
Planting of trees in and around children’s park can provide vitamins and nutrients to children
when they eat the fruit as they play.
6. Ornamental Hedges
Hedges provide a natural background for a garden, as a frame does for a painting. The
hedge may be external or internal. An external hedge—live fence—is usually tall, measuring
about 1.5–2.5 m (5–9 ft) high, and it may replace the compound wall; thus it demarcates the
garden from the public road. It also serves as a protective screen against wind and noise pollu-
tion. Species selected for external hedges should be tall, fast-growing and evergreen, with thick
and dense foliage from the base to the top. The blooms should not clash with the general color
scheme. An internal hedge that separates parts within a garden is not as tall. It is usually 30–90

330 THE BOTANICAL REVIEW
cm (1–3 ft) tall. Species that are capable of growing under adverse conditions and require
minimal maintenance are selected for both types of hedges.
Species of Biota, Cupressus, Ilex, Juniperus, Thuja, etc. are used for evergreen hedges. The
following flowering trees may be used for making colorful hedges: Bauhinia acuminata,
Bougainvillaea spp., Erythrina indica, Hibiscus spp., Meyenia erecta, Plumbago capensis,
Sesbania aegyptica, Strobilanthes spp. and Tecoma stans (Randhawa, 1961).
7. Live Screens and Fences
In cities and towns trees can be utilized for screening the premises of adjacent houses and
thus maintaining privacy. Servants’ quarters and other unsightly views like manure pits, potting
areas, etc. in large gardens can also be screened by growing closely spaced, small trees. Species
with prickles or spines or having stiff branches or both with nonedible leaves should be pre-
ferred, according to the requirements. Ideally, the species selected for this purpose should be
fast growing, of medium height, long-lived, capable of growing under adverse conditions and
with minimal maintenance requirements (Singhal & Khanna, 1991).
8. Sculpture and Topiary
Topiary is an art of shaping hedges—shrubs—and trees into an ornamental form like a ball,
spiral, table, cube, etc., into a figure like a bird, beast or human or into a theme such as a farmer
with a pair of bullocks. A formal garden is most suitable for topiary work because it creates an
Old World appearance. The most common examples used for such purposes are Buxus
sempervirens, Cupressus macropoda, Murraya exotica and Taxus baccata (Randhawa, 1961,
1965–1983).
9. Education
Ornamental trees are not only a source of recreation and pleasure but also educate people,
when visitors in gardens and travelers along roadsides wish to know the names and uses of
such trees. If roads and gardens are named after some dominant shrub and tree species, the
work of making them familiar to the public becomes easier (Chakraverty & Jain, 1984).
10. Landscaping and Bioaesthetic Planning
Shrubs and trees improve the landscape. For example, trees along roadsides are a source of
beauty not only to the road but also to the length and breadth of the area through which the road
runs. Along roads, fuelwood, fodder and thorny species should not be chosen. Shrubs and trees
constitute two of the most important components of landscaping and bioaesthetic planning of
urban cities and towns. Many species bloom at a particular season and appear more effective
when planted in groups (Randhawa, 1961, 1965–1983).
As far as possible, native species should be selected, because, apart from their aesthetic
value, scenic beauty and immediate utility, these trees involve reduced maintenance costs, pre-
serve biological diversity and prevent species extinction. They are also a valuable national
asset and a reserve of timber and fuel in case of emergency. It is estimated that India has the
largest number of flowering trees in the world, indigenous as well as exotic, that can be utilized
for beautifying cities and towns.
It may be mentioned here that bioaesthetic planning of ornamental trees has a close relation-
ship with plant ecology. Plants must be planted only in those localities or habitats that are

TREES AND THEIR ECONOMIC IMPORTANCE 331
similar to their natural habitats or surroundings, because the texture of the soil, the availability
of water resources, the amount of rainfall, the presence of rivers, canals and tanks and the
temperature play an important role in the growth and survival of the trees (Randhawa, 1965–
1983).
Trees must be planted in habitats that are similar to their natural surrounding—i.e., that
have approximately the same edaphic and climatic conditions—otherwise either dwarfing may
occur or the species will not be able to survive. Some examples of ornamental flowering trees
suited to moist localities are Amherstia nobilis, Bauhinia purpurea, Brownea ariza, B. coccinea,
Cassia javanica, C. marginata, C. nodosa, Colvillea racemosa, Guaicum officinale, Lager-
stroemia flos-regine, L. thorelli, Milletia auriculata, Poinciana regia, Peltophorum ferrugineum,
Pithecolobium saman, Saraca indica and Solanum wrightii (Randhawa, 1965–1983).
Examples of ornamental flowering trees suited to dry localities are Acacia auriculiformis,
Butea frondosa, Cassia fistula, Cochlospermum gossypium, Cordia subestena, Erythrina blakei,
E. indica, Jacaranda mimosaefolia, Melia azadirachta, Plumeria alba, Pongamia glabra,
Spathodea campanulata, S. nilotica, Sterculia colorata, Tecomella undulata and Thespesia
populnea (Randhawa, 1965–1983).
Drought-resistant trees suitable for arid regions are Albizia lebbek (siris), Butea frondosa
(dhak), Cassia fistula (amaltas), Casuarina equisetifolia (beefwood tree), Eucalyptus citriodora
(safeda), Melia azedarach (Persian lilac, bakain), Morus indica (mulberry), Phoenix dactylifera
(khajoor), Prosopis juliflora (mesquite bean), Salvadora persica (pilu), etc. (Randhawa, 1965–
1983).
Some examples of salt-resistant trees are Azadirachta indica (neem), Butea frondosa (dhak),
Bassia latifolia (mahua), Eucalyptus citriodora (safeda), Phoenix dactylifera (khajoor), Phyl-
lanthus emblica (amla), Psidium guava (amrood), Tamarix articulata (farash) and Thespesia
populnea (bhendi) (Randhawa, 1965–1983).
Trees for swamps and marshy areas are Eucalyptus rostrata, Salix tetrasperma (willow),
S. babylonica, Sapium sebiferum (makhan), Tamarix articulata (farash), plantain, etc. (Ran-
dhawa, 1965–1983). Sapium sebiferum, known as Chinese tallow tree, is a medium-sized,
deciduous tree whose leaves display lovely autumn tints. It is used for stream training in the
Kangra district of Himachal Pradesh.
11. Veneration
From one end of the world to the other we can trace the extreme power of trees over the
minds of humans. Christmas trees, May trees, pomegranates, Ginkgo biloba, bo trees, etc. can
be cited as occupying a place in the religious and ceremonial activities in diveve cultures through-
out the world. In India alone 99 trees are venerated (Bennet et al., 1992). In ancient times rishis
worshiped several trees as Vrikshadevta and Vanadevta. Groves of trees and flower gardens
were tended with loving care and were called “vrikshavatika” and “pushpavatika,” respec-
tively. Several such protected forest groves or gardens, including Ashoka Vatika, Chitrakoot
and Panchvatti, were known in ancient India.
12. Art and Culture
A tree laden with flowers and/or fruits is a great joy to the beholder. Native trees have a
special place in Indian folk songs. Immortal poets and writers like Valmiki and Kalidasa have
sung songs in praise of trees. Even folktales have celebrated the importance and beauty of trees
in India (Randhawa, 1961, 1965–1983).

332 THE BOTANICAL REVIEW
Indian trees have a personality of their own. The beauty of Indian trees has been sketched or
painted by many artists (Randhawa, 1961, 1965–1983), like Bireshwar Sen and his wife,
Lakshmi, Sarbjeet Singh, Ganga Singh, Anil Roy Chowdhry, Gopal Ghosh, Manishi Day,
Madhava Menon, Devyani Kanwal Krishna, Sudhir Khastgir, Francis Brunell, Madame Sass
Brunner and her daughter Elizabeth, A. K. Gohel, R. A. Eklund, E. Blatter, P. N. Sharma, A. K.
Sharma, H. Smith, Margaret Thacker, G. Millard (Lady Kinnear), Sister Marychionia, Lady
Douie, S. H. Prater, H. Robinson and H. N. Wandrekar. Many of their works have been in-
cluded in books on Indian botany (Seth et al., 2002).
Kalidasa observed that the women of Alkapuri rubbed the dust of lodhra flowers on their
cheeks, maghya flowers decorated their temples, kuruvaka flowers hung from the knots of their
hair and sirisha flowers decorated their ears. Elsewhere, in the monsoon kadamba flowers
glorified women’s heads. The women carried pink lotuses in their hands, decorated their tress
knots with white champaka, wore bracelets of jasmine around their wrists and wore garlands of
jasmine and bela (Randhawa, 1961, 1965–1983).
India’s vast, rich Sanskrit literature contains the names of several trees, including the orna-
mental trees arjuna (Terminalia arjuna), asoka (Saraca indica), champaka (Michelia champaca),
chuta (Mangifera indica), devadaru (Cedrus deodara), gandharaja (Gardenia florida), kadamba
(Anthocephalus cadamba), karnikara (Pterospermum acerifolium), ketaki (Pandanus odora-
tissimus), kimsuka (Butea frondosa), kovidara (Bauhinia purpurea), kunda (Jasminum
pubescens), kuravaka (Lawsonia alba), lodhra (Symplocos racemosa), mandara (Erythrina
indica), naga kesara (Mesua ferrea), narikela (Cocos nucifera), parijataka (Nyctanthes arbor-
tristis), punnaga (Calophyllum inophyllum), sala (Shorea robusta), krishna sirish (Albizia
amara), pitsirish (Albizia lebbek), tala (Borassus flabelliformis) and vakula (Mimusops elengi)
(Randhawa, 1961; Anonymous, 1986; Dwivedi, 2000).
E. TREES AS A SOURCE OF SUSTENANCE
Trees are one of the major sources of sustenance: food; sugars; starches; spices and condi-
ments; beverages; fumitories, masticatories and narcotics; medicines; essential oils; fatty oils
and vegetable fats; waxes; soap substitutes; vegetable ivory; fodder; fuel, bioenergy or biofuel;
fertilizers; fiber; pulp and paper; tannins; dyes; rubber and other latex products; gums; resins;
and cork. These are described separately under the following headings:
1. Food
Trees as a source of food include edible fruits, vegetables and tree legumes. Botanically, a
fruit is a matured or ripened ovary, along with its contents and adhering accessory structures, if
any. The seeds inside the fruits are the fertilized ovules. Sometimes seeds are formed without
fertilization. This phenomenon is called “agamospermy,” a kind of parthenogenesis. A fruit that
matures without seed formation is called “parthenocarpic fruit.” Fruits are eaten raw. Veg-
etables are edible plants that store reserve food—mainly carbohydrates—in roots, stems, leaves
or fruits and that are eaten either cooked or raw. Legumes—or pods—are the proteinaceous
fruits of family Leguminosae. Some of these are edible. The important food-yielding trees are
depicted in Table I.
2. Sugars
Sugar is a plant product surpassed in importance only by cereals and potatoes. It is one of
the most important reserve food supplies, not only for the plant in which it is found but also
also because it serves as the most necessary food—source of energy—for humans. Sugar in
(Text continues on p. 337)

TREES AND THEIR ECONOMIC IMPORTANCE 333
Table I
Trees as a source of food
Common name Genus and species Family Remarks
Tree legumes
Algaroba Prosopis chinensis,P. juliflora Mimosaceae Flowers a source of honey; pods used as
stock feed
Carob bean Ceratonia siliqua Caesalpiniaceae Dried pod edible
Honey locust Gleditsia triacanthus Caesalpiniaceae Pods eaten by animals
Tamarind or imli Tamarindus indica Caesalpiniaceae Pods used for tart; fruits pulp used for
chutney or sauce
Rain tree or vilaiti sirris Samanea saman Mimosaceae Sweet pulp of black pods excellent food
stock
Nittas Parkia biglobosam P. filicoidea, P. roxburghii Mimosaceae Pods and seeds edible
Manila tamarind or jangal jalebi Pithecellobium dulce Mimosaceae Aril edible
Nuts with high fat content
Brazil nut, “neggertoes,” “cream nuts” Bertholletia excelsa Lecythidaceae Contain 65–70% fats and 17% proteins
Cashew nut or kaju Anacardium occidentale Anacardiacae Swollen peduncle, thalamus and cotyledons
edible
Coconut or nariyal Cocus nucifera Arecaceae Endosperm edible
Filbert Corylus avellana Corylaceae Kernels edible
Hazelnut Corylus americana, C. cornuta, C. colurna Corylaceae Kernels edible
Hickory Carya ovata Juglandaceace Kernels edible
Pecan nut Carya illinoensis Juglandaceae Kernels edible
Pilinut Canarium ovatum Burseraceae Seeds edible
Pine nut Pinus edulis, P. gerardiana (Chilgoza),
P. kesiya, etc.
Pinaceae Cotyledons edible
Walnut Juglans nigra, J. regia Juglandaceae Cotyledons edible
European beech Fagus sylvatica Fagaceae
Jangli badam Terminalia catappa Combretaceae
Queensland nut Macadamia turnifolia Proteaceae
Macadamia nut Macadamia turnifolia, M. integrifolia Proteaceae
Nuts with high protein content
Almond Prunus amygdalus Rosaceae Seeds edible
Beechnut Fagus grandifolia, F. sylvatica Fagaceae Seeds edible
Pistachio nut, green almond Pistacia vera Pistaciaceae Seeds edible

334 THE BOTANICAL REVIEW
Table I, continued
Common name Genus and species Family Remarks
Nuts with high carbohydrate content, continued
Acorn Quercus spp. Fagaceae Eaten by animals
Chestnut Castanea dentata Fagaceae Seeds edible
Fruit vegetables
Avocado, alligator pear Persea americana Lauraceae Fruits edible
Breadfruit Artocarpus altilis Moraceae Fruits edible
Jackfruit, kat-hal Artocarpus heterophyllus Moraceae Fruits edible
Pome fruits
Apple, vern. seb Malus pumila, syn. M. domestica Rosaceae Fleshy thalamus edible
Pear, vern. nakh Pyrus communis Rosaceae Fleshy thalamus edible
Quince Cydonia vulgaris Rosaceae Fleshy thalamus edible
Chinese pear or sand pear, vern.
nashpati
Pyrus pyrifolia var. culta Rosaceae Fleshy thalamus edible
Medlar Mespilus germanica Rosaceae Fleshy thalamus edible
Stone fruits
Apricot, vern. khurmani Prunus armeniaca Rosaceae Seeds edible
Cherry, sweet Prunus avium Rosaceae Seeds edible
Cherry, sour, vern. gilas Prunus cerasus Rosaceae Seeds edible
Cherry, Himalayan Prunus cerasoides Rosaceae Seeds edible
Cherry, Himalayan bird Prunus cornuta Rosaceae Seeds edible
Cherry, European bird, vern. jaman Prunus padus Rosaceae Seeds edible
Peach, vern. aru Prunus persica Rosaceae Seeds edible
Plum, vern. alucha, alu-bukhara Prunus domestica Rosaceae Seeds edible
Citrus fruits
Sweet orange, musambi Citrus sinensis Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium
Sour orange, khatta Citrus aurantium Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium
Mandarin orange, santara Citrus reticulata Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium
Pomelo, grapefruit Citrus paradisi Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium

TREES AND THEIR ECONOMIC IMPORTANCE 335
Lemon, bara (pahari) nimbu Citrus limon Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium
Lime, nimbu or kaghzi nimbu Citrus aurantifolia Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium
Shaddock, chakotra Citrus maxima Rutaceae Glandular hairs arising from endocarp
edible; fruit is hesperidium
Other fruits
Emlic, amla Emblica officinalis Euphorbiaceae Fruit rich in tannin and vitamin C; com-
monly pickled and used as medicine;
epicarp and mesocarp of drupe edible
Pineapple, ananas Ananas comosus Bromeliaceae
Mulberry, tut, shahtoot Morus alba, M. australis, M. nigra,
M. rubra, etc.
Moraceae Succulent perianth and fleshy axis edible
Money jack, lakoocha, barhal,
dahrua
Atrocarpus lakoocha Moraceae
Chinese date, jujube, ber, badara Zizyphus mauritiana Rhamnaceae Epicarp and mesocarp of drupe edible
Limeberry, chini narangi Triphasia trifolia Rutaceae
Cherimoya, Hanuman phal, Lakshman
phal
Annona cherimolia Annonaceae Juicy mesocarps of individual berries
edible
Jambolan, jamun, jambaba Syzygium cumini Myrtaceae Epicarp and mesocarp of drupe edible
Wild jujube, jharber Zizyphus nummularia Rhamnaceae Epicarp and mesocarp of drupe edible
Carambola, karmal Averrhoea carambola Averrhoaceae
Bael, bilva Aegle marmelos Rutaceae Inner fleshy layer of pericarp and placentae
edible
Custard apple, sweet sop, sharifa Annona squamosa Annonaceae Inner fleshy layer of pericarp and
placentae edible
Date, pind khajur Phoenix dactylifera Arecaceae Pericarp edible
Fig Ficus carica Moraceae Fleshy receptacle or thalamus edible
Guava, amrood Psidium guajava Myrtaceae Inferior (or false) berries (i.e.. pericarp is
fused with thalamus); epicarp, mesocarp
and endocarp edible
Jujube, ber Zizyphus mauritiana Rhamnaceae Epicarp and mesocarp edible
Litchi Litchi chinensis Sapindaceae Aril edible
Loquat Eriobotrya japonica Rosaceae Fruit is a pome where thalamus is
enlarged to form fleshy, edible part;
pericarp is cartilaginous and encloses
seed-bearing loculi

336 THE BOTANICAL REVIEW
Table I, continued
Common name Genus and species Family Remarks
Other fruits, continued
Mango, aam Mangifera indica Anacardiaceae Fleshy mesocarp edible
Olive Olea europaea Oleaceae Epicarp and mesocarp edible; commercial
olive oil is obtained from fruit pulp and
seeds
Papaya, papeeta Carica papaya Caricaceae
Pomegranate, anar Punica granatum Punicaceae Seeds with juicy testa edible
Sapodila, sapota, chiku Manikara achras Sapotaceae
Kumquat Fortunella japonica Rutaceae
Wild date, khajur Phoenix sylvestris Arecaceae Only one carpel develops into a one-seeded,
edible berry
Gorgan nut, makhana (seeds) Euryale ferox Euryalaceae Seeds edible
Phalsa Grewia subinaequalis Tiliaceae
Durian Durio zibethinus Bombacaceae
Granadilla, passion fruit Passiflora edulis, P. incarnata,P. lauri-
olia,P. lingularis,P. mollissima,
P. quadrangularis
Passifloraceae
Rose apple, gulabjaman Syzygium jambos Myrtaceae Epicarp and mesocarp of drupe edible
Japanese persimon, kaki Diospyros kaki Ebenaceae

TREES AND THEIR ECONOMIC IMPORTANCE 337
plants may occur in the form of sucrose (a disaccharide of glucose and fructose that, to humans,
tastes sweeter than either of its constituent monosaccharides) or cane sugar, glucose or grape
sugar and fructose or fruit sugar. It occurs in roots (beets, carrots, parsnips, etc.), stems (sugar-
cane, maize, sorghum, sugar maple), flowers (palms), bulbs (onion) and many fruits. The im-
portant trees yielding sugars of commercial interest are shown in Table II.
3. Starches
Starch, a complex carbohydrate, is a polymer of glucose units linked by alpha bonds. It
exists in two forms in plants: unbranched or linear polymers called “amyloses,” in which hun-
dreds of glucose molecules form coiled molecules of starch; and branched polymers called
“amylopectins,” in which only 40–60 glucose molecules that form branched chains do not coil.
Soluble starch (starch grains soaked in hot water until they burst and form a thin, clear
solution or paste) is used in the textile industry for strengthening fibers and cementing loose
ends together, making the thread smoother and easier to weave and thus giving a finish to the
goods. It is used as a mordant in calico printing and a thickener or vehicle for colors. It is also
used in laundry work, in toilet powders, in medicine, as a sizing agent in the paper industry, as
binding material for china clay and many derivatives or products like dextrin, glucose, indus-
trial alcohol and nitrostarch.
Starch is one of the main reserve foods for green plants, which store it in thin-walled cells in
the form of grains of different sizes, shapes and microscopic and physical characteristics. The
chief sources of commercial starch are maize, potato, wheat, rice, sago, cassava and arrowroot,
of which the last two are obtained from shrubs and sago is obtained from trees.
Arrowroot starch is obtained from the tubers of many tropical plants, including: Maranta arun-
dinacea (Marantaceae), yielding Indian arrowroot; Canna edulis (Cannaceae), yielding Queens-
land arrowroot; Curcuma angustifolia (Zingiberaceae), yielding East Indian arrowroot; and Zamia
floridanda (Cycadaceae), yielding Florida arrowroot. Only the last is a small, shrublike plant.
Sago starch is obtained from the starchy pith of the stems of Metroxylon sagu, of the family
Arecaceae. Other important species that yield sago starch are: Arenga saccharifera, Borassus
flabellifer, Caryota urens, Metroxylon koenigii, M. leave and M. rumphii, all Arecaceae; Manihot
esculenta, of the family Euphorbiaceae; and Cycas species, of the family Cycadaceae, a gym-
nosperm. Starchy pith is removed after the trees are cut, and, after washing, the starch is freed
by sedimentation. Dried, it is known as “sago flour”; it is made into a flour and then dried in the
sun or in ovens to obtain shiny, granular starch, called “pearl sago.” Both are used almost
entirely for food purposes, like khir, kanji, payasam, kesari, uppuma, vaangibath, sago curd
bhath, vadam (pappad), macaroni and spaghetti.
4. Spices and Condiments
Spices and condiments are flavoring agents obtained from plants. They are difficult to dis-
tinguish, so the terms are used interchangeably. Because they have little nutritive value, they
are not classified as foods. They contain essential oils, which impart flavor and aroma to food
and add greatly to the pleasure of eating. They stimulate the appetite and increase the flow of
gastric juices. For these reasons they are often referred to as “food accessories” or “adjuncts.”
The important spice- and condiment-yielding trees are shown in Table III.
5. Nonalcoholic Beverages
Beverage plants are those plants which yield beverages or drinks—nonalcoholic or alco-
holic—that are palatable and refreshing. Nonalcoholic beverages usually contain caffeine, an

338 THE BOTANICAL REVIEW
Table II
Sugar-yielding trees
Common name Genus and species Family Remarks
Sugar and sap from sweet sap of maples
Sugar maple Acer saccharum Aceraceae Incisions are made through the bark into the sapwood or large roots
and sap is collected, usually in March and April, when tempera-
tures reach 25⬚F at night and 55⬚F during the day; sugar is sucrose
Black maple Acer nigrum Aceraceae
Sugar from unopened inflorescences of palms
Date palm Phoenix dactylifera Aceraceae In wild date palm sugar is obtained from tender upper portions of the
stem; the tips of inflorescences or stems are cut and sweet sap that
oozes out and collected is called “toddy”; its sugar content is about
14%; it is boiled and cooled to obtain hard crude sugar called “jag-
gary,” and it can be fermented to make the beverage called “ar-
rack”; sugar is sucrose
Wild date palm Phoenix sylvestris Aceraceae
Palmyra palm Borassus flabellifer Aceraceae
Coconut palm Cocos nucifera Aceraceae
Toddy palm Caryota urens Aceraceae
Gomuti palm Arenga pinnata Aceraceae
Honey palm Jubaca chinensis Aceraceae
Nipa palm Niga fruticans Aceraceae
Glucose, dextrose or grape sugar Present in edible fruits of many trees and shrubs
Fructose, levulose or fruit sugar Present in edible fruits of many trees and shrubs
Manna or mannose
Manna ash tree Fraxinus ornus Oleaceae The juice oozes out from slits made in the bark and dries into flake-
like a sweet substance called “manna,” used mainly in medicine
Nectar
Gulabi kachnar Bauhinia purpurea Caesalpinae Secreted by attractive flowers of many species in various families;
mainly sucrose, with some glucose and fructose; main food of
bees, which partially digest it; it is thus converted into honey; con-
taining 70–75% invert sugar, proteins, mineral salts and water,
honey is an excellent food for humans and is used in medicine, in
the tobacco industry and in the preparation of mead, a fermented
beverage
Bottle brush Callistemon lanceolatum Myrtaceae
Horse chestnut Aesculus indica Hippocastanaceae
Jamun Eugenia jambolana Myrtaceae
Neem Azadirachta indica Meliaceae
Shisham Dalbergia sissoo Fabaceae
Soapnut Sapindus spp. Sapindaceae
Tun Cedrela toona Meliaceae
Barna Crataeva religiosa Capparidaceae
Chinese tallow Sapium sebiferum Euphorbiaceae
Source: Information on nectar-yielding trees is from Randhawa, 1965–1983.

TREES AND THEIR ECONOMIC IMPORTANCE 339
alkaloid, which has stimulating and refreshing qualities. Alcoholic beverages are those that
contain one or more hydroxyl (–OH) groups; e.g., ethanol (CH3–CH2–OH). They may be fer-
mented or distilled. Fruit juices and other beverages that contain neither caffeine nor alcohol
are called “soft drinks.” They have a high sugar content and thus are a good source of energy.
The important nonalcoholic-beverage woody plants are shown in Table IV.
6. Fumitories, Masticatories and Narcotics
Some narcotic substances are smoked or chewed by humans for pleasure or to seek a “world
full of new sensation or some flight from reality.” Narcotic substances that are used for smok-
ing purposes are called “fumitories,” and those that are used for chewing purposes are called
“masticatories.” They have a distinct stimulating or even narcotic effect due to the presence of
various alkaloids. They are also used in religious ceremonies. The important woody plants of
these categories are shown in Table V.
7. Medicines
Several trees are a source of important drugs. These are obtained from the bark of Bauhinia
variegata (kachnar), Barringtonia acutangula (hijjal), Cinnamomum zeylanicum (dalchini),
C. calisaya, C. ledgerina, C. officinalis, C. robusta, C. succirubra (all yielding quinine), Mimu-
sops elengi (maulsari), Myrica nagi (kaiphal), Symplocos racemosa (lodh), Saraca indica
(ashok), Terminalia arjuna (arjun) and Toddalia asiatica (kanj). The stems and wood of Aca-
cia catechu (katha), Pinus roxburghii (chir) and Santalum album (safed chandan) yield drugs.
Drugs are also obtained from the fruit of Aegle marmelos (bael), Cassia fistula (amaltas),
Emblica officinalis (amla), Terminalia bellerica (bahera) and T. chebula (harar). The seeds of
Croton tiglium (jamalgota), Pongamia pinnata (karanja), Ricinus communis (arand) and Strych-
nos nux-vomica (kuchla) are also used for obtaining drugs.
8. Essential Oils
Like all other necessities of humans, oils are one of the main necessities of daily life. India
holds a prominent position in the world oil industry. Oils are of two types: essential, volatile or
Table III
Spice- and condiment-yielding trees
Common name Genus and species Family Part used
Cassia, vern. tejpat Cinnamomum cassia, syn.
C. tamala
Lauraceae Bark
Dalchini or Ceylon
cinnamon
Cinnamomum zeylanicum Lauraceae Bark
Sassafras Sassafras albidum Lauraceae Root bark
Cloves Syzygium aromaticum Myrtaceae Unopened flower buds
Allspice Pimenta dioica Myrtaceae Fruits
Juniper berries Juniperus communis and
other species
Cupressaceae Mature cones
Star anise or anasphal Illicium verum Apiaceae Fruit
Nutmeg (seed or kernel)
and mace (aril)
Myristica fragrans Myristicaceae Seeds
Sweet bay or laurel Laurus nobilis Lauraceae Leaves

340 THE BOTANICAL REVIEW
Table IV
Important beverage-yielding woody plants
Common name Genus and species Family Part used
Caffeine content
(%)
Coffee Coffea arabica, C. canephora, C. liberica,
C. robusta, C. stenophylla
Rubiaceae Coffee seeds called “beans” 1–1.5
Cocoa or chocolate Theobroma cacao Sterculiaceae Seeds
Maté or Paraguay tea Ilex paraguariensis Aquifoliaceae Leaves
Guarana Paullinia cupana Sapindaceae Seeds 3–4.5
Cola Cola nitida Sterculiaceae Seeds 2
Cassine Ilex vomitoria Aquifoliaceae Fresh or dried leaves and shoots
Yoco Paullinia yoco Sapindaceae Bark 3–4
Coca and cocaine Erythroxylon coca Erythroxylaceae Dried leaves
Table V
Trees used as fumitories and mascatories
Common name Genus and species Family Remarks
Bidi or tendu Diospyros melanoxylon Ebenaceae Dried leaves used for wrapping the tobacco and as a fumitory
Areca, betal nut or supari Areca catechu Arecaceae Betal nuts (drupes) chewed along with pan (leaves of Piper betle)
Catechu, katha, khair or khadira Acacia catechu Mimosaceae Katha obtained from heartwood applied to pan (leaves of Piper betle)
Cola or kola nuts Cola nitida Sterculiaceae Seeds of cola tree used as a masticator in tropical Africa; it contains 2%
caffeine, essential oil and a glucoside, chelonian, which is a heart
stimulant

TREES AND THEIR ECONOMIC IMPORTANCE 341
distilled oils; and fatty, nonvolatile, expressed or fixed oils. These two types of oils can be
distinguished in Table VI.
Essential oils are by-products of carbohydrate and fat metabolism and occur in some 60
families. The important ones are Apiaceae (= Umbellifereae), Asteraceae (= Compositae),
Fabaceae (= Leguminosae), Geraniaceae, Lamiaceae (= Labiatae), Lauraceae, Myrtaceae, Poa-
ceae (= Graminae) and Rutaceae. They occur in small concentrations, from minute traces to as
much as 1–2%, or even more, in specialized cells, glands or ducts, either in one particular
organ of the plant or distributed over many parts. They may be present in flowers (e.g., roses),
fruits (e.g., oranges), leaves (e.g., eucalyptus), bark (e.g., cinnamomum), roots (e.g., ginger),
woods (e.g., cedar) or seeds (e.g., cardamon) and many resinous exudations.
The utility of essential oils to the plant itself is obscure. The characteristic aroma and flavor
they impart to flowers, fruits and seeds probably attract insects and other animals, which play
an important role in pollination and/or in the dispersal of fruits and seeds. When essential oils
are present in high concentrations, the unpleasant odor may serve to repel enemies like para-
sites, animals and insects. The essential oils may have antiseptic and bactericidal properties
Table VI
Differences between essential and fatty (fixed) oils
Essential oils Fatty (fixed) oils
They evaporate or volatilize in contact with air
and hence are called “volatile oils”
They do not evaporate or become volatile when
they come into contact with air and hence are
called “nonvolatile oils”
They can be readily removed from the plant tis-
sues without any change in their composition
and hence are called “distilled oils”
They cannot be distilled without being decom-
posed and hence are called “expressed oils”
They possess a pleasant taste, have a strong, aro-
matic odor and may be colored
They do not possess a strong taste or odor and
are colorless
They are typically liquids At normal (room) or high temperatures they are
either liquids or fluids and are called “oils”;
at normal or cold temperatures they may be
solids or semisolids and are called “fats.”
Quite obviously, what is an oil in a warm
climate may be a fat in a cold climate.
They are very complex in their chemical compo-
sition. The two principal groups are terpenes,
which are hydrocarbons, and oxygenated and
sulphuretted oils.
Chemically these vegetable fatty oils are close to
animal fats. They consist of glycerine and
fatty acid, which is an oleic acid if it is an oil
but stearic or palmatic acid if it is a fat.
They have antiseptic qualities They generally do not possess antiseptic proper-
ties
They are used for diverse purposes, but not as
food
Most of them are edible and are available as food
for humans
Soap is not formed when they are treated with an
alkali
When a fat is boiled with an alkali, it decom-
poses and the fatty acid unites with an alkali
to form soap. If potash or lye is used, a soft
soap is obtained; if soda is used, a hard soap
is obtained.
They can be obtained by distillation, expression
or extraction
They can be obtained by a combination of ex-
pression and extraction, but not by distilla-
tion

342 THE BOTANICAL REVIEW
and may thus act as a wound fluid. They affect transpiration and other physiological processes
by minimizing the effect of heat on transpiration. They play a vital role as hydrogen donors in
oxido-reduction reactions as potential sources of energy.
Because of their odor and high volatility, essential oils are also put to a variety of uses by
humans. They are extensively used in the manufacture of perfumes, sachets, soaps and other
toilet preparations. The perfumes are stored in closed, compactly filled containers since they
deteriorate due to oxidation and polymerization when they come into contact with air. In
confectionary and aerated waters they are used as flavoring materials or essences for ice creams,
candies, cordials, liqueurs, nonalcoholic beverages, tobacco, etc. They are very valuable in
medicine, dentistry and pharmaceuticals because of their therapeutic, antiseptic and bacteri-
cidal properties. They are used as insecticides and deodorants, as solvents in paint and varnish
industries and in the manufacture of several synthetic odors and flavors, such as attars and
scents. Some of the essential oils (e.g., clove oil) are used as clearing or cleaning agents in
histological work. They are also used in such diversified products as chewing gum, toothpaste,
dhoop, agar batis, incense, shoe polish, library paste and fish glue. The important essential oil-
yielding trees are listed in Table VII.
9. Fatty Oils and Vegetable Fats
Vegetable fatty oils are called “fixed oils” or “nonvolatile oils” because they do not evapo-
rate or become volatile like the essential oils. They are also called “nondistilled oils” because
they cannot be distilled without being decomposed.
Chemically, fatty oils consist of glycerin in combination with a fatty acid. The so-called fats or
tallows are solids at ordinary temperatures and contain stearic or palmitic acid. Their iodine num-
ber (the number of grams of iodine absorbed by 100 g of the fats in a medium in which it is soluble)
is below 70. On the other hand, oils are liquids at ordinary temperatures and contain oleic acid.
Oils are of three types: drying, semidrying and nondrying. The drying oils are able to absorb
oxygen and, on exposure, dry into thin elastic film. They are used mainly in the paint and
varnish industry. Their iodine number is higher than 150. The semidrying oils absorb oxygen
slowly and only in limited amounts. They form a soft film only after long exposure. Their
iodine number is between 100 and 150. The nondrying oils remain liquid at ordinary tempera-
tures and do not form a film. Their iodine number is between 70 and 100.
The fatty oils are insoluble in water but soluble in various organic solvents. When a fat is
boiled with an alkali, it decomposes, and the fatty acid unites with the alkali to form soap. If
soda is used, a hard soap is obtained; and if potash or lye is used, a soft soap is obtained.
When fats break down, they yield fatty acids and glycerin, of which they are composed, and
usually develop a rancid odor and taste. The fatty oils are bland (balmy) and lack the strong
taste, odor and antiseptic qualities of essential oils. Thus they are available as indispensable
articles in human food. Important species that yield fatty oils and vegetable fats are listed in
Table VIII.
10. Waxes
Waxes are quite similar to fats but are esters of monohydric alcohols rather than glycerides.
They are harder than fats and have a high melting point. They are less easily hydrolyzed and do
not become rancid. Waxes are usually found on the epidermis of leaves and fruits. They serve
to prevent excessive loss of water through transpiration, because of their impervious character.
The commercially important waxes obtained from trees are shown in Table IX. Wax is also
obtained from the leaves of the raffia and licuri palms, sugarcane and esparto.
(Text continues on p. 349)

TREES AND THEIR ECONOMIC IMPORTANCE 343
Table VII
Essential-oil-yielding trees
Common name Genus and species Family Remarks
Ylang-ylang Cananga odorata Annonaceae Oil is extracted from flower petals. Cananga oil is used in some of the finest
perfumery creations in France; cheaper grades are used in soap making.
Neroli: true oil of neroli or
neroli bigarade
Citrus aurantium Rutaceae Oil is extracted from flowers of the sour orange
Neroli Portugal Citrus sinensis Rutaceae Oil is extracted from flowers of the sweet orange
Mandarin oil Citrus reticulata Rutaceae Oil from peels is used in confectionery, toilet products and pharmaceutical
preparations
Petitgrain oil Citrus spp.; in India,
C. aurantium,
C. limettoides
Rutaceae Oil extracted from leaves and twigs is used to add a pleasant bouquet to
scents, cosmetics, skin creams and soaps
Orange oil Citrus spp.; in India,
C. aurantifoli,
C. reticulata
Rutaceae Oil extracted from ripe peels is used to add a pleasant bouquet to scents, cos-
metics, skin creams and soaps
Bergamot Citrus aurantium subsp.
bergamia
Rutaceae Greenish oil extracted from ripe peels has a soft, sweet odor and is used for
scenting toilet soaps, in mixed perfumes and as a clearing agent
Mexican linaloe Bursera penicillata,
B. glabrifolia
Burseraceae Very aromatic oil extracted from the wood is widely used in perfumes, soaps,
cosmetics, etc. and for flavoring food and beverages
Mysore linaloe Bursera penicillata Burseraceae Very aromatic oil extracted from husks of berries is widely used in perfumes,
soaps, cosmetics, etc. and for flavoring food and beverages
Cayenne linaloe Aniba panurensis Lauraceae Very aromatic oil is widely used in perfumes, soaps, cosmetics, etc. and for
flavoring food and beverages
Brazilian bois de rose Ariba rosaeodora var.
amazonia
Lauraceae Very aromatic oil extracted from the wood is widely used in perfumes, soaps,
cosmetics, etc. and for flavoring food and beverages
Sandalwood oil, vern. safed
chandan
Santalum album and
related spp.
Santalaceae Oil extracted from the wood is largely used as a perfume and in soaps, face
creams and toilet powders. In medicine it has cooling, diaphoretic, diuretic
and expectorant properties. An excellent fixative, it is much used in
blends. The sweet-scented wood is utilized for boxes and chests.
Champaca oil Michelia champaca Magnoliaceae One of the most famous perfumes of India, it is used for various purposes

344 THE BOTANICAL REVIEW
Table VII, continued
Common name Genus and species Family Remarks
Camphor, camphor gum,
mushkapur, camphor oil
Cinnamomum camphora Lauraceae Camphor is solid with tough, white, translucent granule-like masses at ordi-
nary temperatures. Extracted from the wood, twigs and leaves, it is used in
the manufacture of celluloid, nitrocellulose compounds and expensive per-
fumes and in medicine for inflammations, rheumatic pains and sprains, as
a cardiac stimulant and to relieve diarrhoea. The by-product is called “sa-
frole.”
Cedarwood oil Juniperus virginiana Cupressaceae Oil extracted from the heartwood is valuable as a clearing agent in the prepa-
ration of permanent microscopic mounts and for use with oil-immersion
lenses because of its high refractory index. It is also used in soaps, per-
fumes, liniments, deodorants and cleaning and polishing preparations and
as an adulterant of geranium and sandlewood oils. Because of its insecti-
cidal properties it is utilized as a moth repellent and in fly sprays.
Deodar oil Cedrus deodara, Junipe-
rus macropoda
Pinaceae, Cupres-
saceae
The variants of cedarwood oil used in India are obtained from chips, sawdust
or wood of Cedrus deodara and from the shavings and sawdust of Junipe-
rus macropoda
Clove oil, vern. loung-
ka-tel
Syzygium aromaticum Myrtaceae Oil extracted from flower buds is used in perfumes, soaps, confectionery and
medicine, as a stimulant, carminative and in flatulence and as a clearing
agent in histological work for microscopy
Oil of turpentine, pine oil Pinus spp. Pinaceae Oil from resins is used in the manufacture of varnishes, lacquers, disinfec-
tants, paints, linoleum, sealing wax, oilcloth, lubricating compounds, inks,
etc.
Cinnamon oil Cinnamomum zeylanicum Lauraceae Oil from chips and waste bark is used in the preparation of cinnamon quills
and as denitifrices and perfumes
Eucalyptus oil Eucalyptus citriodora,
E. dives, E. globulus,
etc.
Myrtaceae Oil from the leaves and terminal branchlets is a source of citronellal, citronel-
lol and menthol. It is widely used in perfumery, as a mosquito repellent,
germicide and disinfectant and in medicine in the treatment of asthma and
bronchitis.
Nutmeg oil Myristica fragrans Myristicaceae Oils from nutmeg (the aromatic kernels) and mace (the arils) of the fruits of
Myristica fragrans (vern. jaiphal) are used externally to treat rheumatism
and in soaps and perfumes. Oil obtained from the leaves is used in the
preparation of chewing gum, flavoring essences and cosmetics.

TREES AND THEIR ECONOMIC IMPORTANCE 345
Macassar oil Schleichera trijuga Sapindaceae Extracted from seeds of the gum-lac tree (vern. gausam), the oil has a valuable
stimulating and cleansing effect on the scalp, promoting hair growth. It is
also used to cure skin diseases, itches, rheumatism and headaches.
Agar oil, agar attar Aquillaria agallocha Thymelaeaceae Agar oil, from resinous portions of the wood, is pale yellow to brownish yel-
low or dark amber in color. It is used in perfumery and as an incense. True
agar is heavier than water.
Keora oil, attar of kewda,
attar keora, keora water,
sandali attar, kewda or
oil kewda
Pandanus tectorius
(= P. odoratissimus)
Pandanaceae Screwpine flowers are unusually large: a single flower weighs up to 150 g.
The oil is used in the preparation of fragrant hair oils, perfumes, etc.
Cajeput oil Melaleuca leucadendron Myrtaceae Oil extracted from fresh leaves and twigs is used in pharmaceuticals as throat
lozenges, gargles, etc. and in medicine as a remedy for colds, throat dis-
eases, headaches, etc.
Elengi oil Mimusops elengi Sapotaceae The essential oil, from bulletwood flowers, is a pale yellow, mobile liquid
with a very delicate, sweet and tenacious floral odor. It is used in the
manufacture of perfumes.

346 THE BOTANICAL REVIEW
Table VIII
Fatty-oil- and vegetable-fat-yielding trees
Common name Genus and species Family Remarks
Drying oils from seeds
Tung oil Aleurites fordii, A. montana Euphorbiaceae Used in the paint and varnish industry; also used for waterproofing
wood, paper and fabrics, and therefore valuable for outdoor
paints
Kekuna, candle nut,
lumbang oil
Aleurites moluccana Euphorbiaceae Used in making paint, varnish, lacquer, linoleum and soft soap
Walnut oil Juglans regia Juglandaceae Mature and old kernels yield a drying oil. An edible oil, it is also
used for white paint, artists’ oil paints, printing ink and soap.
Laurelwood oil Calophyllum inophyllum Guttiferae Used as an illuminant, for soap making and to treat rheumatism
Margosa oil Azadirachta indica Meliaceae Used as an antiseptic and for burning purposes
Oiticia oil Licania rigida Rosaceae Used in the paint and varnish industry; also used in making linoleum
and printing inks and for improving the elasticity of rubber prod-
ucts
Nondrying oils from seeds
Castor oil Ricinus communis Euphorbiaceae Used as a purgative, a lubricant and an illuminant; also used in
soaps, the textile industry, typewriter inks, perfumes, varnishes
and paints
Olive oil Olea europaea Oleaceae Used mainly as salad and cooking oil; also used in soap making, as a
lubricant and in medicine
Vegetable fats
Coconut oil Cocos nucifera Arecaceae Dried coconut meat yields oil. Refined coconut oil is edible. Used
for cooking, confectionery, making candy bars, soap, cosmetics,
shaving cream, shampoo and other toilet preparations and also as
an illuminant.
Palm oil, palm-kernel oil Elaeis guineensis Arecaceae Extracted from the fibrous pulp of nuts and from kernels. Used in
making soap and margarine and as a fuel for diesel engines; also
used for making glycerin, shampoo, soap and candles.

TREES AND THEIR ECONOMIC IMPORTANCE 347
Mahua oil, mowra or bassia fat;
mahua or illipe butter
Madhuca indica Sapotaceae Oil obtained from seeds is used mainly in the manufacture of laun-
dry soap and also in making candy, in the jute industry, and to
treat skin diseases, rheumatism, headache, constipation, piles,
etc.
Phulwara butter Diplokneura butyracea
(= Madhuca butyracea)
Sapotaceae Oil obtained from seeds is used mainly in the manufacture of laun-
dry soap and also in making candy, in the jute industry, and to
treat skin diseases, rheumatism, headache, constipation, piles,
etc.
Carapa oil Xylocarpus moluccensis Meliaceae Oil obtained from seeds is used for soap and as an illuminant
Nutmeg butter Myristica fragrans Myristicaceae Seeds contain about 40% of a yellow fat, used in soap, ointment,
perfumes and candles and also to treat rheumatism
Pongam oil Pongamia pinnata Papilionaceae Oil obtained from seeds is used for soap making, as an illuminant,
and in the treatment of skin diseases and rheumatism
Babassu oil Orbignya martiana,
O. oleifera
Arecaceae Oil obtained from nuts is used as a substitute for coconut oil and for
making bullet-proof glass, explosives and lubricants
Cohune oil Orbignya cohune Arecaceae Oil obtained from nuts is used as a substitute for coconut oil and for
making bullet-proof glass, explosives and lubricants
Licuri oil Syagrus coronata Arecaceae Oil obtained from nuts is used as a substitute for coconut oil and for
making bullet-proof glass, explosives and lubricants
Murumuru oil Astrocaryum murumuru,
A. tucuma, A. vulgare
Arecaceae Oil obtained from nuts is used as a substitute for coconut oil and for
making bullet-proof glass, explosives and lubricants
Cocoa butter Theobroma cacao Sterculiaceae Fat obtained from beans is used for cosmetics and perfumes, as a
base for ointments and as a lubricant for massaging
Shea butter Butyrospermum parkii Sapotaceae The fat is edible and is used as a substitute for cocoa butter and in
making soap and candles
Borneo tallow Shorea aptera Dipterocarpaceae Fat from kernels is used for soap making and as a substitute for co-
coa butter
Chinese vegetable tallow Sapium sebiferum Euphorbiaceae Obtained from a thick layer of hard, white fat on seeds, it is used in
soap, cosmetics and candles. Seeds yield drying oil, used for
paints, varnishes and plastics and as an illuminant.
Macassar oil Schleichera oleosa Sapindaceae Oil from seeds is used in cooking, as a hair oil and for illumination
Ucuhuba butter, otoba butter Virola spp. Myristaceae Used for various purposes

348 THE BOTANICAL REVIEW
Table IX
Wax-yielding trees
Common name Genus and species Family Remarks
Carnauba wax Copernicia cerifera Arecaceae The most important vegetable wax from the wax palm tree (the “tree of life” in Bra-
zil), it occurs as an exudation on leaves and is used in the manufacture of can-
dles, soap, high-luster varnish, paint, car wax, shoe polish, carbon paper,
batteries, insulation, phonograph records, salve, sound film, ointment, etc.
Wax tree Ceroxylon andicola Arecaceae Used as a substitute for carnauba wax
Myrtle wax Myrica pensylvanica,M. cerifera Myricaceae Berries are covered with thick layer of wax, used for the manufacture of soap and
candles with a pleasant fragrance
Japanese wax Rhus succedanea Anacardiaceae Berries yield wax, used in the manufacture of candles, wax matches, pencils, leather,
furniture polish, soap and lipstick and in the vulcanization of rubber
Table X
Saponin-yielding trees
Common name Genus and species Family Remarks
Soap nut or soap
berries, vern.
ritha
Sapindus emarginatus,
S. mukorossi,
S. saponaria
Sapindaceae Used as a soap substitute for washing hair and woolen, silken and other delicate fab-
rics; also used in the preparation of hair tonic
Soapbark Quillaja saponaria Rosaceae Dried inner bark contains 9% saponin, used for washing delicate fabrics, cleaning
lenses and precision instruments, as an expectorant and emulsifying agent in
medicine and in the manufacture of shampoo, cosmetics and hair tonic

TREES AND THEIR ECONOMIC IMPORTANCE 349
11. Soap Substitutes
Saponins are a group of water-soluble glucosides that yield soap froth in water, form emul-
sions with oils and fats, and are capable of absorbing large amounts of gases such as carbon
dioxide. Because of these properties they are used for cleansing and other purposes, both at
home and in industry. The important saponin-containing trees are listed in Table X.
It may be added here that leaves of a familiar garden plant, bouncing bet or soapwort
(Saponaria officinalis, family Caryophyllaceae), when placed in water, produce a lather that is
utilized for washing and imparting luster to silk and woolen fabrics. Similarly, bulbs of the
Californian soaproot (Chlorogalum pomeridianum, family Liliaceae) yield a good lather, which
is utilized for washing fabrics.
12. Vegetable Ivory
The seeds of Phytelephas macrocarpa, in the family Arecaceae, commonly called “ivory
nut” or “tagua palm tree,” is the chief source of vegetable ivory. It is extensively used as a
substitute for true ivory. It can be carved and used in the manufacture of buttons, chess pieces,
poker chips, dice, knobs, inlays, billiard balls, toys, etc. Metroxylon amicarum, in the Arecaceae
family, can likewise be used for these purposes.
13. Fodder
The leaves of trees and shrubs are rich in calcium and phosphorus. Although considered
inferior to grasses, trees in different parts of India are lopped for fodder, especially when grasses
are scarce. The important fodder-yielding trees are Acacia nilotica (= A. arabica), A. catechu,
Acer spp., Aegle marmelos, Bauhinia variegata, Celtis australis, Dendrocalamus strictus, Ficus
glomerata, F. religiosa, Grewia spp., Helicteres isora, Kydia calycina, Leucaena leucocephala,
Melia azedarach, Millettia auriculata, Morus australis, M. serrata, Ougeinia oojeinsis, Populus
ciliata, Quercus glauca, Q. incana, Zizyphus mauritiana and Z. nummularia (Singh, 1982; Anony-
mous, 1983).
14. Fuel, Bioenergy or Biofuel
Bioenergy is the energy available from biological sources, both living and immediate re-
mains. Fuel is any material that burns readily in air. Biofuels are materials of biological origin
that are used for producing heat and other forms of energy. Fuel is a great necessity of modern
life. Wood, peat and coal, which represent three stages in the carbonization of the original
woody plant tissue, are important fuel substances.
Because their moisture content is lower than that of green wood, seasoned or oven-dried
wood makes excellent fuel: 99% of it is combustible, so it leaves only a small amount of ash.
Hardwoods, such as ash, beech, hickory, maple and oak, which burn for a longer time and
provide more uniform heat than does gymnospermic wood, are excellent fuelwoods. The mean
calorific value of oven-dried Indian hardwoods is about 9000 btu. The different forms of en-
ergy that can be obtained from wood are shown in Table XI.
The qualities needed for fuelwood are physical properties of the wood as well as environ-
mental and silvicultural properties of the species. Small-diameter, thornless shrubs and trees,
which are easy to cut with primitive tools and easy to transport, are generally preferred. Like-
wise, fuelwood that is easy to split and either has a low moisture content or dries rapidly is
preferred over other wood, because considerable heat is lost in burning moist wood. Such
wood is also nontoxic and produces less smoke. For health reasons, too, these are important

350 THE BOTANICAL REVIEW
Table XI
Forms of energy obtained from wood
Process Form of energy
Direct burning Heat, fire
Gasification Producer gas
Carbonization (the process of heating wood and
converting it into carbon)
Charcoal (has twice as much heating power as
wood and burns without flame or smoke)
Pyrolysis Charcoal, gas, oil
Hydrolysis, fermentation Ethanol
Gasification, synthesis Methanol
fuelwoods: ventilation is poor in village houses. While burning, wood should neither split nor
spark. Wood density is positively correlated with the calorific value of fuelwood. A negative
correlation also exists between wood density and growth rate, so fast-growing species gener-
ally have inferior burning properties. The best fuelwood species burn slowly and produce good
heat from glowing charcoals. Acacia and Casuarina spp. are regarded as the best fuelwood
species (Singhal & Khanna, 1991).
Some common fuelwood species of India are Acacia catechu, A. leucocephala, A. nilotica
var. cupressiformis, A. nilotica var. indica, Albizia amara, A. lebbek, Anogeissus latifolia,
Azadirachta indica, Borassus flabellifer, Carrissa spinarum, Dalbergia sissoo, Delonix elata,
Eucalyptus spp., Euphorbia spp., Leucaena leucocephala, Mangifera indica, Melia azedarach,
Moringa tinctoria, Morus serrata, Pithecellobium dulce, Prosopis juliflora, P. spicigera, Psidium
guajava, Sesbania sesban, Syzygium cuminii, Tamarix indica, Thespesia populnea, Zizyphus
mauritiana, etc. (Singhal & Khanna, 1991).
15. Fertilizers
Several species of nitrogen-fixing bacteria of Rhizobium, including R. leguminosarum,
R. lupini, R. meliloti and R. phaseoli, live inside the root nodules of leguminous trees. Simi-
larly, Frankia, a nitrogen-fixing mycelial bacterium, is associated symbiotically with the root
nodules of several nonlegume plants, including Alnus, Casuarina, Coriaria, Myrica and Ru-
bus. Both Rhizobium and Frankia are capable of fixing atmospheric nitrogen. When the roots
of these plants decay, they enrich the soil with nitrogen salts.
16. Fibers
Botanically, a fiber is a special type of cell (sclerenchymatous) that has thick walls, a narrow
lumen and tapering ends. Chemically, it is made up of cellulose and lignin. Commercially, a
plant fiber is a strand consisting of one or hundreds of cells that varies in length from a fraction
of a millimeter to 2 meters or more. Depending on how fibers are used, they can be classed as
textile fibers (for fabrics, netting, cordage), brush fibers, plaiting and rough weaving fibers (for
hats, sandals, baskets, chairs, etc.), filling fibers, natural fabrics and papermaking fibers.
The important fiber-yielding woody plants, including trees and shrubs, are Abroma angusta,
Abutilon spp., Acacia leucocephala, Ananas comosus, Antiaris toxicaria, Boehmeria nivea,
Borassus flabellifer, Butea monosperma, Caryota urens (leaves), Cordia dichotoma, C. rothii,
Ficus bengalensis, F. cunia, F. religiosa, Grewia glabra, G. elastica, G. optiva, G. tiliaefolia,
G. vestita, Hardwickia binata, Hibiscus spp., Malachra capitata, Marsdenia volubilis, Panda-
nus spp. (leaves), Sterculia foetida, S. urens, S. villosa, Trema orientalis and Urena lobata.

TREES AND THEIR ECONOMIC IMPORTANCE 351
Most fibers are obtained from the bark of these plants. Silky flosses produced in the fruits of
Bombax ceiba, Ceiba pentandra and Cochlospermum religiosum are also used as fibers for
filling purposes. The well-known coir fiber is obtained from the fibrous mesocarp of the coco-
nut palm, Cocos nucifera. It is coarse, stiff, buoyant and elastic and is therefore used for ship
ropes, mats, brushes, ropes, etc. (Watt, 1889–1893; Anonymous, 1983; Maithani et al., 1991).
17. Pulp and Paper
An important use of fibers is in the manufacture of paper, which is playing an increasingly
important role in modern civilized society. It can be divided into two categories: cultural paper
(printing and writing paper) and industrial paper (packing and wrapping papers and boards).
The word “paper” comes from the Latin papyrus (the name of Cyperus papyrus of the
family Cyperaceae), a sedge plant, the pith of which was used for paper in Egypt as early as
2400 B.C. The Chinese, however, were the first to actually make the paper. In 1799 Louis
Robert of France invented the papermaking machine, which was improved by Henry and Sealy
Fourdrinier of London in 1803.
The important and major raw materials of the pulp and paper industry are wood fibers
(furnishing more than 90% of all the paper produced in the world), cotton and linen rags
(yielding fine grades of paper, because of their high cellulose content), agricultural residues
(bamboo, bagasse, straw, etc.) and waste paper (for recycled paper). Raw materials of minor
importance are esparto grass (Stipa tebnacissima, family Poaccae), textile fibers (jute, hemp,
coir, ramie, sisal hemp, sunn hemp, etc.), bast fibers of paper mulberry (Broussonetia papyrifera,
family Moraceae) and fibers of papyrus (Cyperus papyrus), baobab (Adansonia digitata) and
Daphne cannabina. Chinese and Japanese rice paper is made from Tetrapanax papyriferum,
Edgeworthia tomentosa and Wickstroemia canescens.
Generally, softwood tracheids are preferred over hardwood fibers for papermaking because
the tracheids of conifers are longer (about 2–4 mm) than are hardwood fibers (0.5–1.5 mm).
Spruce wood is the most important raw material for pulp. Its fibers are long and strong, with a
maximum content of cellulose. Almost free of resins, gums and tannins, it is light colored,
sound and usually free of defects. The important species used are Picea rubens (red spruce),
P. glauca (white spruce), P. sitchensis (sitka spruce), etc.
The other important raw materials for pulp are pines, other conifers and hardwoods, like
Pinus australis (yellow pine), P. banksiana (jack pine), Tsuga canadensis (eastern hemlock),
T. heterophylla (western hemlock), Abies balsamea (balsam fir), A. concolor (white fir), Larix
laricina (tamarack), Populus tremuloides and P. grandidentata (aspens), Fagus grandifolia
(beech), Acer saccharum (sugar maple) and Betula lutea (birch).
Although ancient Indian written records are on the leaves of the tree called “bhojpatra”
(Betula alnoides, family Betulaceae), the art of papermaking in India started with the installa-
tion of first papermaking machine at Serampore in West Bengal in 1830. The main fibrous raw
materials for papermaking are Bambusa arundinacea, Boswellia serrata, Dendrocalamus
strictus, Eulaliopsis binata (Sabai grass) and Pinus roxburghii. These are followed by Abies
pindrow, Adansonia digitata, Agave americana, Arundo donax, Bambusa polymorpha, B. tulda,
Broussonetia papyrifera, Daphne papyracea, Dendrocalamus giganteus, D. hamiltonii, Euca-
lyptus citriodora, E. globulus, Ochlandra travancorica and Populus ciliata. The following
Indian hardwood species are used for making bleachable pulp: Albizia lebbeck, Anogeissus
latifolia, Chloroxylon swietenia, Gmelina arborea, Lannea coromandelica, Prosopis chilensis,
Pterocarpus marsupium, Sesbania grandiflora, Sterculia urens, Tectona grandis and Terminalia
bellerica.

352 THE BOTANICAL REVIEW
(Text continues on p. 357)
18. Tannins
Tannins are soluble, astringent, bitter and complex phenolic substances of plant origin.
These are glycosidal in nature and acidic in reactions. They may be hydrolizable or condensed
in nature. Whereas hydrolyzable tannins are easily split into alcohols and acids by water, con-
densed tannins are not, for they are made up of polymers of cyclic compounds. Tannins may be
present in individual cells or in special containers known as “tannin sacs.” In individual cells,
tannins are found in the cell sap or are impregnated in the cell’s walls, often accumulating in
large quantities in dead tissues such as cork or present in bark, wood, leaves, roots, fruits and
galls.
The biological functions of tannins are not very clear. It is thought that tannins protect the
protoplast against desiccation, decay and injury by animals. It may be concerned with the
formation of cork or with protection of the plant. Economically, tannins are important in vari-
ous ways. They have the ability to unite with certain types of proteins, such as those in animal
skins (hides), to form a strong, flexible, resistant and insoluble substance known as “leather.”
The process and art of converting raw hides and skins of animals into leather, usually through
the use of certain chemicals, is called “tanning.” Tannins react with salts of iron to form dark
blue, blue-black or greenish black compounds, which are the basis of tannin or writing inks.
Tannins are also useful in medicine, because of their astringent nature. Tanning materials are
often utilized in oil drilling to reduce the viscosity of the drill without reducing the specific
gravity. Tannins may be obtained from the different parts of the trees, as shown in Table XII.
19. Dyes
Dyes are colored compounds (pigments) that are capable of being fixed to fabrics perma-
nently; i.e., they neither fade on exposure to light nor wash out with soap. Therefore, a colored
organic substance is not necessarily a dye. For example, trinitrotoluene, which is yellow in
color, cannot fix to a cloth and therefore is not a dye. On the other hand, picric acid, which is
also yellow in color, can fix to a cloth and therefore is a dye. A large number of plants secrete or
contain pigments, but only about 150 are commercially important. In addition, synthetic or
aniline dyes are now obtained from coal-tar products. These are cheaper, brighter, more perma-
nent and easier to use, and they offer a wider range of colors. Among the chief uses of dyes is
in coloring fabrics in the textile industry, where they are used with weak salt solutions of
various metals like iron, chromium, aluminum or tin. A fine layer of metallic oxide, which
forms an insoluble compound with the dye, is deposited on the cloth. Such salts of metals that
increase the adherence of various dyes to the fabrics are called “mordants.” These actually form
a chemical bridge between the fiber molecules and the dye. Dyes are also used for coloring
paints, varnishes, leather, ink, paper, wood, furs, food, cosmetics and medicines. A partial list
of important dye-yielding trees in given in Table XIII.
20. Rubber and Other Latex Products
Rubber is obtained from the milky juice or latex of various tropical or subtropical woody
plants. Latex is a gummy white liquid full of minute globules, a mixture of water, hydrocar-
bons, resins, oils, proteins, acids, salts, sugars and caoutchoue, a substance used as a source of
rubber. Rubber is a polyterpene consisting of a long chain of thousands of isoprene (hydrocar-
bon) units. The tissue containing latex is called “laticiferous tissue.” It consists of latex cells or
latex coenocytes and latex vessels, the latter being formed by the fusion of many latex cells.
Laticifers occur in bark, leaves and other softer parts of trees.

TREES AND THEIR ECONOMIC IMPORTANCE 353
Table XII
Tannin-yielding trees
Common name Genus and species Family Remarks
Tannins obtained from bark
Mangrove Aegiceras corniculatum, Bruguiera con-
jugata, B. cylindrica, B. parviflora,
Rhizophora candelaria
Rhizophoraceae Bark is very hard and heavy and contains 22–33% tannin;
extract is the cheapest source of tanning material
Wattle Acacia dealbata, A. decurrens, A. leuco-
cephala, A. mearnsii, A. mollis,
A. nilotica, A. polyacantha
Mimosaceae Wattles contain 40–50% tannin. Bark, removed when trees
are 5–15 years old, is ground to a powder. Pods also con-
tain tannin. Wattles yield a very firm, pink leather, used
for soles.
Avaram Cassia auriculata Caesalpiniaceae Contains 18–23% tannin; used for tanning
Konnai bark Cassia fistula Caesalpiniaceae Contains 10–12% tannin; used for tanning
Sumac Rhus mysurensis Anacardiaceae Used for tanning
Arjun Terminalia arjuna Combretaceae Contains 20–24% tannin; used for tanning
Indian almond Terminalia catappa Combretaceae Used for tanning
Jujube Zizyphus mauritiana, Z. nummularia,
Z. oenophlia
Rhamnaceae Used for tanning
Ceriops Ceriops roxburghiana Rhizophoraceae Bark contains 20–37% tannin; leaves, 9–15%
Cuddaph almond Buchanania lanzan Anacardiaceae Used for tanning
Casuarina Casuarina equisetifolia, C. suberosa Casuarinaceae Used for tanning
Sal Shorea robusta Dipterocarpaceae Bark contains 3–9% tannin; used for tanning
Pomegranate Punica granatum Punicaceae Bark and fruit used for tanning
Hog plum Spondias pinnata Anacardiaceae Used for tanning
Oak Lithocarpus densiflora, Quercus alba,
Q. borealis, Q. infectorea, Q. leuco-
trichophora, Q. montana, Q. velutina
Fagaceae Bark contains 6–30% tannin; used for tanning
Mallet Eucalyptus occidentalis Myrtaceae Bark contains 35–50% tannin
Hemlock Tsuga canadensis, T. heterophylla Pinaceae Bark contain 8–30% tannin; used for tanning
European larch Larix decidua Pinaceae
Norway spruce Picea abies Pinaceae
Tanekaha bark Phyllocladus trichomanoides Podocarpaceae

354 THE BOTANICAL REVIEW
Table XII, continued
Common name Genus and species Family Remarks
Tannins obtained from wood
Chestnut Castanea dentata, C. sativa Fagaceae Wood contains 30–40% tannin
Quebracho Schinopsis balansae, S. lorentzii Anacardiaceae Wood, known as “axe breaker,” is one of the hardest known
woods; its specific gravity is 1.30–1.40. Wood contains
40–60% tannin; used for tanning.
Tannins obtained from leaves
Sumac Rhus copallina, R. glabra, R. mysurensis,
R. punjabensis, R. succedanea, R. ty-
phina
Anacardiaceae 10–25% tannin in leaves / leaf galls; used for tanning
Smoke tree, Indian sumac Cotinus coggyria Anacardcaceae Used for tanning
Gumghatti, dhawa sumac Anogeissus latifolia Combretaceae Leaves contain 32–39% tannin; used for tanning
Sicilian sumac Rhus coriaria Anacardiaceae Leaves contain 20–35% tannin
Tannins obtained from fruits
Myrobalan Terminalia bellerica, T. catappa, T. che-
bula, T. citrina, T. tomentosa
Combretaceae Nuts contain 30–40% tannin; used for tanning
Emblic myrobalan Emblica officinalis Euphorbiaceae Tannin content 28% in fruit, 21% in twigs, 8–9% in stems,
22% in leaves
Divi divi Caesalpinia coriaria, C. digyna Caesalpiniaceae Pods contain 40–50% tannin; used for tanning
Wild jujube Zizyphus xylocarpa Rhamnaceae Used for tanning
Pomegranate Punica granatum Punicaceae Fruit shells and bark used for tanning
Tora Caesalpinia spinosa Caesalpiniaceae Fruits contain 43–51% tannin; used for tanning and making
ink and as a black dye
Algarobilla Caesalpinia brevifolia Caesalpiniaceae Used for tanning
Valonia Quercus macrolepsis Fagaceae Sun-dried acorn cups contain 45% tannin; used for tanning
Tannins obtained from roots
Palmetto Sabal palmetto Arecaceae Tannin content in roots is low (10%)

TREES AND THEIR ECONOMIC IMPORTANCE 355
Table XIII
Dye-yielding trees
Common name Genus and species Family Remarks
Dyes obtained from wood
Logwood Haematoxylon campechianum Caesalpiniaceae Heartwood contains purplish red dye; with iron salts it be-
comes black; used for making inks and in histological
work as a stain; also used for dyeing
Cutch Acacia catechu, A. catechuoides,
A. sundra
Mimosaceae Heartwood contains 44–69% catechin; used as a dyeing
stuff, as a masticatory and in medicine; cutch is the by-
product
Sappan wood, Brazil wood,
Braziline
Caesalpinia echinata, C. sappan Caesalpiniaceae Heartwood yields a red dye; used for dyeing cotton and
wool and for preparing red ink
Red sandalwood, red sanderswood,
santaline
Pterocarpus santalinus Papilionaceae Heartwood yields a red dye; used for dyeing cotton and
wool and for preparing red ink
Fustic Chlorophora tinctoria Moraceae Natural yellow, brown and olive dyes obtained from heart-
wood are used for dyeing
Osage orange Maclura pomifera Moraceae Bright orange wood yields orange-yellow, gold and green
dyes
Camwood Baphia nitida Fabaceae Redwood dye is obtained
Barwood Pterocarpus erinaceous, P. soyauxii Papilionaceae Yields shades of brown, red and violet dyes
Artocarpus Artocarpus heterophyllus,
A. lakoocha
Moraceae Yields bright yellow dye; used by Buddhist monks
Dyes obtained from leaves
Lodh Symplocos crataegoides Symplocaceae Yellow dye is obtained
Chlorophyll a (C
55
H
72
O
5
N
4
Mg),
Chlorophyll b (C
55
H
70
O
6
N
4
Mg);
all green plants
Used for coloring food, soap and similar products
Dyes obtained from roots and tubers
Indian mulberry Morinda angustifolia, M. brac-
teata, M. citrifolia, M. tinctoria
Rubiaceae Roots yield red and yellow dyes

356 THE BOTANICAL REVIEW
Table XIII, continued
Common name Genus and species Family Remarks
Dyes obtained from bark
Bishopwood Bischofia javanica Euphorbiaceae Red and tan dyes are obtained
Teak Tectona grandis Verbenaceae Yields yellow dye for coloring baskets
Quercitron Quercus velutina Fagaceae Yields bright yellow dye used for dyeing
Lokao, buckthorn Rhamnus globosa, R. utilis Rhamnaceae Yields green dye used for dyeing silks and cottons
Dyes obtained from flowers
Flame of the forest, dhak Butea monosperma Papilionaceae Yields yellow dye used in Holi festivals
Tree of sorrow Nyctanthes arbor-tristis Oleaceae Yields orange dye used for coloring silk and cotton
Sweet indrajao Wrightia tinctoria Apocyanaceae Yields blue dye
Red cedar Toona ciliata Meliaceae Yields yellowish red dye used for dyeing cotton
Dyes obtained from fruits
Kamla, kamela Mallotus philippinensis Euphorbiaceae Yields red dye used for dyeing silk
Dyes obtained from seeds
Annatto Bixa orellana Bixaceae Used for coloring foodstuffs as well as wools, paints, var-
nishes and soaps
Dharauli Wrightia tomentosa Apocyanaceae Yields yellow dye
Dyes obtained from different parts
Gum resin, gamboge Garcinia cambogia, G. cowa,
G. hanburyi, G. morella,
G. xanthochymus
Guttiferae Pith, flowers, leaves and fruits yield a yellow emulsion
used for making watercolors and gold-colored spirit
varnishes for metals

TREES AND THEIR ECONOMIC IMPORTANCE 357
Laticifers are not known in gymnosperms. They are present in a large number of species and
genera belonging to about 20 families, mostly dicotyledonous. Important rubber plants belong
to Apocyanaceae, Euphorbiaceae and Moraceae.
Latex performs five functions in plants: healing of wounds; protection (warding off the
attack of animals) because of the presence of bitter or poisonous alkaloids; storage of food
reserve (for nutrition); formation and storage of excretory products; and transport of materials
(conduction or translocation or as a fluid reservoir).
Joseph Priestley, the discoverer of oxygen, coined the term “rubber,” owing to the fact that
it could be used for removing pencil marks. In 1839 Charles Goodyear discovered the vulcani-
zation process, in which sulphur is added to rubber to cross-link the molecules of isoprene
chains. This process makes the latex impervious to weather conditions and improves its elastic-
ity. Rubber is one of the best insulating and dielectric materials available. The important rub-
ber-yielding woody plants are shown in Table XIV.
21. Gums
Gums contain large amounts of sugars and are closely allied to pectins. They are colloidal in
nature and have the ability to dissolve in water and form a viscid solution (viscous liquids) or
to absorb water and swell to form a gelatinous paste. On exposure to air these pastes dry to
hard, clear, glassy masses by losing their water. Gums are insoluble in alcohol and ether.
Gums exude naturally or in response to wounding from the stems and are formed by disin-
tegration of internal tissues, mostly from the decomposition of cellulose through a process
known as “gummosis.” They are mostly obtained from bark or secondary phloem.
Gums are used in a variety of ways. The finer grades are utilized in finishing silk, clarifying
liqueurs and preparing high-quality watercolors. The intermediate grades are used in printing
inks, in sizing, finishing and dyeing textile fabrics, in confectionery and in the pharmaceutical
industry. The cheaper grades are used as adhesives, in calico printing, in sizing of paper and in
the paint industry. In the cosmetic and pharmaceutical industries gums act as emollients or
demulcents or serve to bind or emulsify mixtures in lotions, ointments and creams. They may
add body and bulk to foodstuffs like commercial ice creams.
Commercial gums are dried exudations of dry-region plants belonging to the Anacardiaceae,
Combretaceae, Fabaceae, Meliaceae, Rosaceae and Rutaceae.
One hundred or more species of
Acacia alone are known to yield gum. The important gum-yielding trees are shown in Table XV.
22. Resins
Although resins resemble gum in superficial appearance, they differ in origin and chemical
composition. Some resins are sticky, viscous liquids; others are hard, brittle, amorphous solids,
generally clear or transparent but sometimes opaque. Important resin-yielding families, differ-
ences among three main types of resins and resin-yielding trees are presented in Tables XVI,
XVII and XVIII, respectively.
Resins represent oxidation products of various essential oils. They are complex and varied
in their chemical composition. Chemically, they are polymerized terpenes that are usually mixed
with volatile oils. Unlike gums, resins are insoluble in water but soluble in alcohol, ether,
turpentine, spirit, carbon disulphide and other solvents. The latter property is utilized to form
varnishes; when applied in thin films, the solvent evaporates, leaving behind a hard, water-
proof layer of resin. Resins are fusible; that is, when heated they first soften and then melt to a
more or less clear, sticky fluid. They are resistant to most reagents and to decay but, when
ignited, burn with a smoky flame.
(Text continues on p. 370)

358 THE BOTANICAL REVIEW
Table XIV
Rubber-yielding trees
Common name Genus and species Family Remarks
Elastic rubber
Hevea or Pará rubber Hevea brasiliensis Euphorbiaceae 98% of the world’s rubber comes from this tree, which is native to Amazo-
nia; in India it is a plantation crop in Kerala, Tamil Nadu and Karnataka
Castilla or Panama rubber Castilla elastica Moraceae Native to Mexico and Central America
Caucho rubber Castilla ulei Moraceae Native to Amazonia
Ceará or Manicoba rubber Manihot glaziovii Euphorbiaceae Native to Brazil; also grown in India
Assam or India rubber Ficus elastica Moraceae Native to northern India and Malaysia; of low grade and little commercial
value
Mangabeira Hancornia speciosa Apocyanaceae Native to Bolivia, Brazil and Paraguay
Chilte rubber Cnidosceolus spp. Euphorbiaceae
Nonelastic rubber
Gutta-percha Pelaquium ellipticum,
P. gutta, P. polyan-
thum
Sapotaceae Obtained from grayish white latex of this Malaysian tree; latex, present in
sacs that occur in the cortex, phloem, pith and leaves, is used for insula-
tion, submarine cables, golf balls, waterproofing and adhesives and as a
substitute for chicle
Balata Manilkara bidentata Sapotaceae Native to Trinidad and South America; used for insulation, submarine ca-
bles, golf balls, waterproofing and adhesives and as a substitute for
chicle
Jelutong Dyera costulata Apocyanaceae A Malayasian tree; used as a substitute for chicle
Chicle, sapodilla, naseberry Manilkara achras Sapotaceae Native to the Yucatán Peninsula, cultivated in India; latex contains 20–25%
gutta-percha–like gum called “chicle,” which is the basis of the chewing
gum industry; also used in making surgical tape and dental supplies
Sorva, leche caspe Couma macrocarpa Apocyanaeae A large Amazonian tree; used as a substitute for chicle

TREES AND THEIR ECONOMIC IMPORTANCE 359
Table XV
Gum-yielding trees
Common name Genus and species Family Remarks
Gum arabic, kumta Acacia senegal Mimosaceae Gum obtained from bark; used for all purposes mentioned in the text
Khair Acacia catechu Mimosaceae Gum obtained from bark; used for all purposes mentioned in the text
Babul, acacia, kikar Acacia nilotica Mimosaceae Gum obtained from bark; used in confectionery
Acacia Acacia modesta Mimosaceae Used in medicine and in printing calico
Son khair, kaiger Acacia ferruginea Mimosaceae Gum obtained from bark; used for all purposes mentioned in the text
Karaya, kandya, katira,
kuteera, katillo, kullo,
India or sterculia gum
Sterculia urens, S. villosa Sterculiaceae Gum obtained from heartwood; used as a substitute for gum tragacanth,
also in the cosmetic and cigar industries in several emulsions, lotions,
pastes and as a laxative; forms a strong adhesive gel with a little wa-
ter
Gum ghatti Anogeissus latifolia Combretaceae Used as a substitute for gum arabic; also used in ceramics, foods and the
petroleum industry, as a drilling mud conditioner, and in the explo-
sives industry
Gum locust, carob Ceratonia siliqua Caesalpiniaceae Not a true gum because it is obtained not from wounded woody tissues
but from the endosperm of seeds; was used by Egyptians as an adhe-
sive for binding mummies, now used in the food industry and for
other purposes mentioned in the text
Cellulose gum, caboxy-
methyl cellulose gum;
green plants
Prepared by mixing purified cellulose with sodium monochloroacetate in
an alkaline medium; extra whitening and brightening of detergents is
due to this gum; also used in the paper, textile, food and paint indus-
tries
—Limonia acidissima Rutaceae Substitute for gum arabic
Hog gum Cochlospermum religiosum Cohlospermaceae Substitute for gum arabic; is edible
Cycas gum Cycas circinalis Cycadaceae
Larch gum Larix occidentalis Pinaceae Gum obtained from wood chips; used as a substitute for gum arabic
Mesquite gum, kabuli kikar Prosopis chilensis, P glandu-
losa, P. juliflora
Mimosaceae Gum obtained from stems; used for printing calico
Cherry gum Prunus cerasoides, P. cerasus Rosaceae Used as a substitute for gum arabic

360 THE BOTANICAL REVIEW
Table XV, continued
Common name Genus and species Family Remarks
East Indian copal Canarium bengalense Burseraceae Gum obtained from stems; used as a hard-drying varnish
Gum benzoin, benjamin Styrax benzoin Styracaceae Source of benzoic acid
Jhingan gum Lannea coromandelica Anacardiaceae Used in printing calico and as sizing in the paper and textile industries
Malabar kino gum Pterocarpus marsupium Papilionaceae Valuable medicine in diarrhea and dysentery
Bengal kino Butea monosperma Papilionaceae Valuable medicine in diarrhea and dysentery
—Astragalus prolixus Papilionaceae Gum obtained from stems; used in cosmetics, printing calico and confec-
tionery
Garmezu Astragalus strobiliferus Papilionaceae Gum obtained from stems; used in confectionery
Gum neem Azadirachta indica Meliaceae
Wood apple, kut bel Feronia limonia Rutaceae Gum obtained from trunk and branches; used as a substitute for gum
arabic
Bialam Anisoptera scaphula Dipterocarpaceae
Cowa Garcinia cowa Guttiferae Gum obtained from trunk and branches; used for preparing yellow var-
nish
Semla gond Bauhinia retusa Mimosaceae Substitute for gum arabic; used for sizing cloth and paper and for water-
proofing terraced roofs
Albizia gums Albizia chinensis, A. lebbek,
A. odoratissima, A. procera
Mimosaceae Used for various purposes
Bauhinia gums Bauhinia purpurea, B. race-
mosa, B. variegata
Mimosaceae
—Chloroxylon swietenia Rutaceae Yields amber or reddish brown gum
Mango Mangifera indica Anacardiaceae Substitute for gum arabic
—Terminalia bellerica Combretaceae Contains crystals of calcium carbonate
—Terminalia tomentosa Combretaceae Used as incense

TREES AND THEIR ECONOMIC IMPORTANCE 361
Table XVI
Resin-yielding families
Family Resin
Gymnosperms
Pinaceae Calophony, balsam, Canada balsam, kauri-resin, manil copal,
oleo-resin, sandarac
Fossil conifers Amber (from Pinus succinifera)
Angiosperms
Anacardiaceae Mastic
Apiaceae Ammoniacum, asafoetida, galbanum
Berberidaceae Podophyllum
Burseraceae Elemi, frankincense, myrrh
Caesalpiniaceae Copal
Convolvulaceae Jalap, seamony
Dipterocarpaceae Dammars
Guttiferae Gamboge
Hamamelidaceae Storax
Liliaceae Acaroid resin, aloes, dragons blood
Leguminosae (Fabaceae) Balsam of perum, Congo copal, copaiba balsam, Peru balsam,
tolu balsam
Styracaceae Benzoin
Zygophyllaceae Guiacum
Table XVII
Differences among three main types of resins
Hard resins Oleo resins Gum resins
Little, if any, essential oil Considerable essential oils as
well as resinous materials
Mixture of both true gums and
resins, thus contain small
amounts of essential oils
and traces of coloring matter
Usually solid, more or less
transparent, brittle sub-
stances
More or less liquid in nature Occur naturally as milky exuda-
tions, collected as tears or
irregular masses
No particular odor or taste Distinct aroma and flavor May have an aroma and flavor
Nonvolatile and very poor con-
ductors of electricity but be-
come negatively electrified
when friction is applied;
readily fusible and burn in
air with a smoky flame
Volatile essential oil component
Common examples: copals, da-
mars
Common examples: balsams,
elemis, turpentines
Common examples: anmoni-
acum, asafoetida, galbanum

362 THE BOTANICAL REVIEW
Table XVIII
Resin-yielding trees
Common name Genus and species Family Remarks
Hard resins
Zanzibar copal, Madagascar copal,
Mozambique copal
Trachylobium verrucosum Fabaceae Hardest of all copals except amber; living, semifossil or fossil in
nature; yellowish to brownish red
Inhambane copal Copaifera conjugata Fabaceae
Congo copal, Angola copal Copaifera aemeusii,
C. mopane
Fabaceae Living as well as fossil in nature; light yellow
Sierra Leone copal Copaifera copallifera,
C. salikounda
Fabaceae Light yellow
Accra copal, Benin copal Daniella ogea Fabaceae Locally called “ogea gum” in Liberia, Ghana and Nigeria
South American copal, Demerara
copal, Pará copal
Hymenaea courbaril Fabaceae Softest of all copals
Manila copal Agathis alba Araucariaceae Living, semifossil or fossil in nature; yellow
Kauri copal, kauri gum Agathis australis Araucariaceae Living, semifossil or fossil in nature; yellow
Damar mata kuching Hopea micrantha Dipterocarpaceae
Damar penak Balanocarpus heimii Dipterocarpaceae
Damar temak Shorea hypochra Dipterocarpaceae
Sal damar, guggal dhuma, ral
dhuma, lal dhuma
Shorea robusta Dipterocarpaceae Used as an ingredient of “samagri,” which is burned in religious
ceremonies
Kala damar Shorea tumbuggaia Dipterocarpaceae Used as an incense and in marine yards as a substitute for pitch
White damar, piney resin, Indian
copal, dhupa
Vateria indica Dipterocarpaceae Used in medicine to treat chronic bronchitis, diarrhea and rheuma-
tism
Black damar Canarium strictum Burseraceae Used as a substitute for burgundy pitch in medical plasters
Batavian damar Shorea wiesneri Dipterocarpaceae
Rock damar Hopea odorata Dipterocarpaceae Used in varnishes

TREES AND THEIR ECONOMIC IMPORTANCE 363
Amber Pinus (= Pinites)succini-
fera (principal source)
Pinaceae Fossilized terpenoid resin occurring on the shores of the Baltic Sea,
it is the only jewel of plant origin. It is exceedingly hard, brittle,
yellow to brown or even black, transparent or opaque with a
characteristic aromatic odor; when rubbed, it takes a high polish
and becomes negatively charged. Used for beads, ornaments,
mouthpieces of pipes and holders for cigars and cigarettes, etc.
Sometimes organisms of the past are embedded in it.
Amber Hymenaea spp., Copaifera
spp. (other sources)
Fabaceae Fossilized terpenoid resin occurring on the shores of the Baltic Sea,
it is the only jewel of plant origin. It is exceedingly hard, brittle,
yellow to brown or even black, transparent or opaque with a
characteristic aromatic odor; when rubbed, it takes a high polish
and becomes negatively charged. Used for beads, ornaments,
mouthpieces of pipes and holders for cigars and cigarettes, etc.
Sometimes organisms of the past are embedded in it.
Lacquer Rhus verniciflua, R. suc-
cedanea
Anacardiaceae Natural varnish exuded from Asiatic trees, it affords protection be-
cause it remains unchanged by acids, alkalis, alcohol or heat up
to 160⬚F
Rhus succedanea yields liquid resin from the mesocarp of fruits,
which is used in ointments, wax varnishes, etc.
Burmese lacquer, thitsi Melanorrhoea usitata Anacardiaceae Affords protection because it remains unchanged by acids, alkalis,
alcohol or heat up to 160⬚F
Shellac Butea monosperma,
Cajanus cajan
Papilionaceae Not strictly a plant product but a resinous substance secreted on the
twigs of many trees by the sap-feeding stick lac insect Tachar-
dia lacca (“lacca” is derived from the Sanskrit word laksha,
meaning “lakh”). Used in the manufacture of phonograph rec-
ords, high-grade insulators, spirit varnish, sealing wax, drawing
ink, watercolors, nitrocellulose lacquers and as sizing in paper
and stiffening in felt hats.
Shellac Schleichera oleosa Sapindaceae Not strictly a plant product but a resinous substance secreted on the
twigs of many trees by the sap-feeding stick lac insect Tachar-
dia lacca (“lacca” is derived from the Sanskrit word laksha,
meaning “lakh”). Used in the manufacture of phonograph rec-
ords, high-grade insulators, spirit varnish, sealing wax, drawing
ink, watercolors, nitrocellulose lacquers and as sizing in paper
and stiffening in felt hats.

364 THE BOTANICAL REVIEW
Table XVIII, continued
Common name Genus and species Family Remarks
Hard resins, continued
Shellac Zizyphus xylopyrus Rhamnaceae Not strictly a plant product but a resinous substance secreted on the
twigs of many trees by the sap-feeding stick lac insect Tachar-
dia lacca (“lacca” is derived from the Sanskrit word laksha,
meaning “lakh”). Used in the manufacture of phonograph rec-
ords, high-grade insulators, spirit varnish, sealing wax, drawing
ink, watercolors, nitrocellulose lacquers and as sizing in paper
and stiffening in felt hats.
Shellac Ficus religiosa Moraceae Not strictly a plant product but a resinous substance secreted on the
twigs of many trees by the sap-feeding stick lac insect Tachar-
dia lacca (“lacca” is derived from the Sanskrit word laksha,
meaning “lakh”). Used in the manufacture of phonograph rec-
ords, high-grade insulators, spirit varnish, sealing wax, drawing
ink, watercolors, nitrocellulose lacquers and as sizing in paper
and stiffening in felt hats.
Shellac Acacia nilotica Mimosaceae Not strictly a plant product but a resinous substance secreted on the
twigs of many trees by the sap-feeding stick lac insect Tachar-
dia lacca (“lacca” is derived from the Sanskrit word laksha,
meaning “lakh”). Used in the manufacture of phonograph rec-
ords, high-grade insulators, spirit varnish, sealing wax, drawing
ink, watercolors, nitrocellulose lacquers and as sizing in paper
and stiffening in felt hats.
Acaroid or grass-tree resins Xanthorrhoea hastilis,
X. tateana, X. australis
Liliaceae Resin collected around the bases of old leaves is yellow from the
first species and red from the other species. Used in making
sealing wax and spirit varnishes and as a substitute for rosin in
paper sizing and ink; also as a source of picric acid and in medi-
cine.
Sandarac Tetraclinis articulata, Cal-
litris quadrivalvis
Cupressaceae Secreted in the form of small tears on the bark, it is hard, white and
rather brittle. Used for coating labels, negatives, cardboard
leather and metal and in dental cement, incense and fumigating
powder.

TREES AND THEIR ECONOMIC IMPORTANCE 365
Chios mastic Pistacia lentiscus Pistaciaceae Excreted from the bark in the form of long, ovoid, pale yellow, brit-
tle tears. Used for coating metals and both oil and watercolor
pictures; in the preparation of transparent varnishes and in
chewing gum; also used in perfumery, medicine, lithographic
work and as a cement for dental work.
Bombay mastic Pistacia cabulica Pistaciaceae Dull, milk-colored resin. Used for coating metals and both oil and
watercolor pictures; in the preparation of transparent varnishes
and in chewing gum; also used in perfumery, medicine, litho-
graphic work and as a cement for dental work.
Malbar, gum or Indian kino Pterocarpus marsupium Fabaceae Used in medicine for throat troubles and in tanning
West African kino Pterocarpus erinaceus Fabaceae Red resin, used in medicine for throat troubles and in tanning
Bengal kino Butea monosperma Fabaceae Used in medicine for throat troubles and in tanning
Gum kino Eucalyptus camaldulensis Myrtaceae Secreted between the wood and the bark
Gum kino Dipteryx odorata, Coc-
coloba uvifera
Polygonaceae Secreted between the wood and the bark
Lesch Antiaris toxicaria Moraceae White resin, used for poisoning arrows and in medicine
Oleoresins
Turpentine, birja, biroja, lisha,
lassa
Pinus australis, P. cari-
baea, P. ponderosa (in
America); P. rox-
burghii, P. wallichiana,
P. merkusii, P. insu-
laris, P. kesiya (in In-
dia); P. pinaster,
P. maritima (in
France); P. pinaster,
P. halepensis, P. nigra,
P. pinea (in Spain);
P. pinaster, P. pinea (in
Portugal); P. halepensis
(in Greece); P. sylves-
tris (in Russia, Poland
and Germany)
Pinaceae Exuded from coniferous trees as a viscous, honey-like liquid or a
soft, sticky substance called “pitch.” On distillation it yields
essential oil (called “oil” or “spirit of turpentine”) and rosin (the
residue). The oil is used in the paint and varnish industry, in
printing cotton and wool, as a solvent for rubber and gutta-
percha, in medicine and in the manufacture of pine oil, terpi-
neol, camphor, pine tar, vormeol, voneol acetate and other
chemicals. The rosin, or colophony, is a brittle, friable, faintly
aromatic, solid used in the manufacture of soap, varnish, paint,
oilcloth, linoleum, sealing wax, adhesives, printers’ ink, floor
and roof coverings, rubbers, drugs, plastics, etc. and as a sizing
material for paper. Rosin oil is used as grease, a lubricant and a
solvent.

366 THE BOTANICAL REVIEW
Table XVIII, continued
Common name Genus and species Family Remarks
Oleoresins, continued
Venetian turpentine Larix decidua Pinaceae Used in histology, lithographic work, varnishes and veterinary
medicine; yellowish or greenish liquid with a characteristic taste
and odor
Bordeaux turpentine Pinus pinaster Pinaceae The residue, called “Burgundy pitch,” is a stimulant and counterirri-
tant and is used in plastics, ointments and pharmaceuticals
Strasbourg turpentine Abies alba Pinaceae The residue, called “Burgundy pitch,” is a stimulant and counterirri-
tant and is used in plastics, ointments and pharmaceuticals
Jura turpentine Picea abies Pinaceae
Canada balsam Abies balsamea Pinaceae True turpentine (oleoresin) from the balsam fir, it is a viscid, yel-
lowish or greenish substance used as a mounting medium for
microscopic work and a cement for optical lenses; also used as
an irritant, stimulant and antiseptic, as a component in collodion
and many plasters and as a fixative for soap and perfumes.
Technically, balsams are aromatic oleoresins that contain ben-
zoic or cinnamic acid and are less viscous and contain less oil
than turpentines. On distillation balsams yield essential oils that
are used in medicine and as fixatives in the perfume industry.
Oregon balsam Pseudotsuga taxifolia Pinaceae A viscid, yellowish or greenish substance used as a mounting me-
dium for microscopic work and a cement for optical lenses; also
used as an irritant, stimulant and antiseptic, as a component in
collodion and many plasters and as a fixative for soap and per-
fumes
Spruce gum Picea rubens Pinaceae Obtained from wood and bark, the oleoresin is thin, clean, bitter and
sticky, hardens on exposure to air and has a pleasing, resinous
taste. Used as a masticatory because it softens in the mouth and
becomes reddish.

TREES AND THEIR ECONOMIC IMPORTANCE 367
Balsam of Peru Myroxylon pereirae Fabaceae A dark, reddish brown, thick, viscous, syrupy liquid obtained by
wounding the tree. Used in medicine for treating slow-healing
wounds and skin diseases (especially during World War II) and,
because of its stimulating and antiseptic effect on mucous mem-
branes, for treating coughs, bronchitis, etc.; also used as a sub-
stitute for vanilla, as a fixative in perfumes and in the soap
industry. The common name is a misnomer because the tree
grows in Central America, not in Peru.
Balsam of Tolu Myroxylon balsamum Papilionaceae A brown or yellowish brown, plastic substance with a pleasant aro-
matic taste and odor; used for almost the same purposes as bal-
sam of Peru
Levant styrax or storax Liquidamber orientalis Hamamelidaceae A semiliquid, sticky, grayish brown, opaque, aromatic substance
obtained from inner bark by wounding the tree; used in cosmet-
ics, soap, adhesives, lacquers and incense as a fixative, in per-
fumes and in medicine for the treatment of coughs and scabies
American styrax Liquidamber styraciflua Hamamelidaceae A clear, thick, brownish yellow semisolid or solid substance ob-
tained from inner bark by wounding the tree; used in cosmetics,
soap, adhesives, lacquers and incense; as a fixative in perfumes;
and in medicine for the treatment of coughs and scabies. India
imports it from France.
Siam benzoin, balsamic resin Styrax benzoides, S. tank-
inense
Styraceae Yellowish or brownish, pebble-like hard and brittle tears with a
milky white center and a strong, vanilla-like aroma; used as in-
cense and in medicine as a stimulant, diuretic, carminative and
expectorant; in the manufacture of perfume, soap, toilet water,
lotion, tooth powder and fumigating materials; a source of ben-
zoic acid
Sumatra benzoin Styrax benzoin Styraceae Reddish or grayish brown tears that aggregate to form blocks or
lumps; used as incense and in medicine as a stimulant, diuretic,
carminative and expectorant; in the manufacture of perfume,
soap, toilet water, lotion, tooth powder and fumigating materi-
als; a source of benzoic acid

368 THE BOTANICAL REVIEW
Table XVIII, continued
Common name Genus and species Family Remarks
Oleoresins, continued
Copaiba, Copaiba balsam, capaiva Copaifera spp., espe-
cially C. officinalis,
C. reticulata
Fabaceae Obtained by boring holes into heartwood, it is a thin, clear, color-
less liquid that turns yellow and viscid with age, is aromatic and
has a bitter taste; used in making lacquer, varnish and tracing
paper, as a fixative in perfume and soap; in photography for
half-tones and shadows and in medicine as a laxative, disinfec-
tant, diuretic and mild stimulant
Gurjan balsam Dipterocarpus alatus,
D. indicus,
D. turbintus
Dipterocarpaceae Thick, opaque and grayish, it is used in medicine and for caulking
and varnishing boats
Illurin balsam, African copaiba,
Sierra Leone frankincense
Daniella oliveri,
D. thurifera
Fabaceae Thick, very fragrant, pungent, pepper-like oleoresin
Manila elemi Canarium luzonicum Burseraceae Oozes from trunk bark in fragrant, white masses on tree trunks;
used locally for torches, for caulking boats, in lithographic
work, in the manufacture of cements, adhesives and ink, in per-
fume, in medicine, in plastics and ointments, and in the varnish
industry to make products tough and elastic
African elemi Boswellia frereana Burseraceae
Mexican elemi Amyris balsamifera,
A. elemifera
Rutaceae
Brazilian elemi Bursera gummifera,
Protium heptaphyl-
lum
Burseraceae
Mecca balsam Commiphora opabal-
samum
Burseraceae A greenish, turbid oleoresin with an odor of rosemary; used in
incense, perfumes and medicine
Mexican linaloe Bursera penicillata Burseraceae Obtained from the aromatic fruits; used in perfume
Salai gum, Indian olibanum Boswellia serrata: Burseraceae Used as an incense, in medicine for rheumatism, nervous diseases
and ointments and as a fire lighter

TREES AND THEIR ECONOMIC IMPORTANCE 369
Gum resins
Ammoniacum Dorema ammoniacum Apiaceae Exudes from stems and flowering branches as a milky juice that
hardens on exposure to form brittle, brownish yellow tears,
which occur singly or in masses; used in perfumery and in
medicine as a circulatory stimulant
Herabol myrrh Commiphora myrrha Burseraceae Oozes from stems as a pale yellow liquid that hardens to form
brown or black tears; used in perfumery, as a constituent of
mouthwash and dentifrices and in medicine as a tonic, stimulant
and antiseptic
Bisabol, sweet myrrh Commiphora erythraea Burseraceae Used in incense, perfumes and embalming and as a constituent of
Chinese joss sticks
Gum resin Commiphora caudata Burseraceae A pale yellow liquid that gradually solidifies and turns brown or
black; used in medicine, as incense and for embalming
Frankincense of olibanum Boswellia carteri Burseraceae Exudes from bark as a clear, yellow resin that hardens into small
yellow grains; used in incense and perfumes and as a fixative
for face powders, pastilles and fumigating powders
Indian frankincense, luban Boswellia serrata Burseraceae Obtained from bark, the oleo-gum-resin contains: oily, turpentinic
liquid, used as a substitute for turpentine oil; a rosin-like resin,
used in the soap industry; and gum, used in printing calico
Opopanax Commiphora kataf Burseraceae Used in perfumery and in medicine
Opopanax Opopanax chironium Apiaceae An herb used in perfumery and in medicine
Ceylon gambose, Indian gamboge Garcinia hanburyi,
G. morella
Guttiferae Yellow emulsion obtained from the pith, leaves, flowers and fruits;
used in preparing watercolors and gold-colored spirit varnishes
and in medicine as a violent cathartic
Madar Calotropis gigantea,
C. hamiltonii
Asclepiadaceae Used as a substitute for gutta-percha

370 THE BOTANICAL REVIEW
Resins are very important in industry. Two types are used in manufacturing varnishes and
lacquers. The first type comprises resins that, after melting, can be combined with linseed oil or
turpentine and utilized for forming amber, copal and other oil varnishes. Oil varnishes are
superior but costly.
The word “copal” is of Mexican origin. In England many of the harder copals are known as
“animes.” The copals are resins of recent semifossil or fossil tropical and subtropical tree spe-
cies. They contain almost no oil and yield a hard, elastic varnish, which is much used for
outdoor work.
The second type of resins comprises those that dissolve in alcohol, turpentine or other
volatile solvents. They are utilized for forming spirit varnishes, such as rosin, damar, sandarac,
mastic and elemis. Spirit varnishes are less expensive and more easily prepared and applied.
They produce brilliant, transparent finishes. All damars are used chiefly in spirit varnishes and
in the manufacture of nitrocellulose lacquers. Damar varnishes are softer, less durable and
adhere better. They are used mainly for varnishing paper because of their luster and light color.
They are also used for indoor work and in histology. “Elemi” is a collective name for several
oleoresins of different origin that exude as clear, pale liquids. Most tend to harden on exposure,
but some may remain soft.
Resinous substances have been used for waterproof coatings and also for decorative coat-
ings for ages. The ancient Egyptians varnished their mummy cases, and the Incas utilized resins
in their embalming mixtures. Resins are also used in the preparation of soap—they dissolve in
alkali to form soap—and in medicine, for sizing paper, as a stiffening material for mats, in the
preparation of fixatives, incenses, perfumes, tobacco flavorings, sealing wax, plastics, lino-
leum, oilcloth, printers’ ink, adhesives, etc. Their combustible properties are utilized for mak-
ing torches; their waterproofing qualities, for making boats.
Resins tend to lessen the amount of water lost from the tissues of plants. Because of their antisep-
tic properties, resins prevent decay, and, when present in wood, add strength and durability.
Resin is secreted in plant tissues in specialized canals or cavities called “resin ducts,” which
are lined with a special layer of secretory cells, called the “epithelial layer,” that secrete resin
into the cavity through a thin cuticular layer. Resin ducts may be present in leaves, wood and
bark of stems. They normally ooze out through the bark and harden on exposure to air. Com-
mercial resins, however, are extracted from artificial wounds or fossil materials.
23. Cork
Commercial cork is obtained from the outer bark (phellem) of cork oak, Quercus suber, an
evergreen tree of the family Fagaceae. It is native to the western Mediterranean region: about
70% of the world’s commercial cork comes from Portugal alone. Cork is nothing more than
thin-walled but strong cellulosic cell walls, which are heavily coated with suberin, a substance
that is impervious to water. Cell lumens, which represent nearly 53% of the total cork volume,
are filled with air, thus making cork very light—its specific gravity is 0.15–0.25.
Cork is buoyant, light and highly compressible, but it is resilient, chemically inert to mois-
ture and common liquids, resistant to deterioration, an excellent insulator, a nonconductor of
electricity, a low thermal conductor and impervious to water and other liquids. It imparts no
flavor or odor to substances, is slow to catch fire, absorbs sound and vibrations and has a high
coefficient of friction. All of these properties render commercial cork invaluable in the world
market, and it is used either as natural cork or as composition cork, the latter as linoleum,
linotiles, binder-coated cork and cork (insulation) boards. Cork is used in the preparation of
stoppers, hats and helmets, tips for cigarettes, carburetor floats, fishing-net floats, golf-club
handles, penholders, fishing rods, life preservers, floats and life jackets, surf balls, seals for

TREES AND THEIR ECONOMIC IMPORTANCE 371
jars, sealing liners, shoe insoles, sporting goods, picture frames, small cork balls in referees’
whistles, etc.
24. Food for Silkworms
Mulberry silk accounts for 95% of the world’s silk production. It is produced by Bombyx
mori L., which feeds on the leaves of mulberry plants. Morus is the Latin word for “mulberry”
(French: muries; Italian: gelso; Japanese: lewwa). It belongs to the family Moraceae, of the
order Unisexuales or Urticales. The following species of Morus are known in the world: acidosa,
arabica, atropurpurea, australis, bombycis, boninensis, cathayama, celtidifolia, cordatifelia,
indica, glabrata, insignis, japonica, kagayamae, laevigata, latifolia, lhou, macroura, micro-
phylla, miyabean, mizuho, mollis, mongolica, mosozygia, multicaulis, nigra, nigriformis,
notabilis, pabularia, philippinensis, rotundifolia, rubra, serrata, sinensis, tiliaefolia and
yoshimurai (Seth & Lal, 2002).
Tasar silk is the product of the secretion from the silk glands of Antheraea proylei and
A. mylitta, the temperate and tropical tasar silkworms, respectively. Although Antheraea spe-
cies are polyphagous in nature, the food plants of first choice are known as “primary” and
others, as “secondary.” The three main food plants of tropical tasar silkworms are: Terminalia
alata, syn. T. tomentosa, vern. asan; Terminatia arjuna, vern. arjun; and Shorea robusta, vern.
sal. In addition to the three main food plants, the tasar silkworm may feed on the following
(Seth, 2000a):
•Anogeissus latifolia; axlewood, vern. dhawa, dhaura, dhaunta; family Combretaceae,
order Myrtales
•Bauhinia variegata; vern. kachnar; family Caesalpiniaceae, order Rosales
•Bombax ceiba, syn. Salmalia malabarica, Bombax malabaricum, Gossampinus mala-
barica; silk cotton tree, vern. semul, shembal, raket-senbal, kaanti sembal, pagun; fam-
ily Bombacaceae, order Malvales
•Canthium dicoccum, syn. C. didymum, Plectronia didyma; vern. rangruri; family Rubi-
aceae, order Rubiales
•Capadessa fruiticosa: vern. nalbali; family Meliaceae, order Geraniales
•Careya arborea; kumbi, vern. kumbi; family Lecythidaceae, order Myrtales
•Carissa carundus; karunda, vern. karumcha, karaunda; family Apocynaceae, order
Gentianales
•Celastrus paniculatus; vern. malkangni; family Celastraceae, order Celastrales
•Chloroxylon swietenia; East Indian satinwood, vern. bhirra, girya; family Rutaceae, or-
der Geraniales
•Dodonaea viscosa; vern. aliar, sinatha; family Sapindaceae, order Sapindales
•Ficus benjamina; family Moraceae, order Unisexuales or Urticales
•Ficus religiosa; peepal, vern. pipal, pipli; family Moraceae, order Unisexuales or Urticales
•Ficus retusa; vern. kamrup, chilkan; family Moraceae, order Unisexuales or Urticales
•Ficus tsiela; vern. jari; family Moraceae, order Unisexuales or Urticales
•Ficus tsjakela; family Moraceae, order Unisexuales or Urticales
•Hardwickia binata; anjan, vern. anjan; family Caesalpiniaceae, order Rosales
•Lagerstroemia indica; common crape myrtle, vern. saoni; family Lythraceae, order
Myrtales
•Lagerstroemia parviflora; landau, vern. Sida, dhaura, Bali, Sidi; family Lythraceae, or-
der Myrtales
•Madhuca indica, syn. M. latifolia, Bassia latifolia; mahua, mowra, illipe, butter tree,
vern. mahua, mohwa, mauwa; family Sapotaceae, order Sapindales

372 THE BOTANICAL REVIEW
•Melastoma malabathricum; vern. phutki; family Melastomataceae, order Myrtales
•Ricinus communis; castor, castor seed, vern. erandi, bharenda; family Euphorbiaceae,
order Euphorbiales
•Shorea roxburghii, syn. S. talura; lac tree of South India; family Dipterocarpaceae, or-
der Parietales
•Syzygium cuminii, syn. Eugenia jambolana, E. cuminii; jaman, jambolan, blackplum,
java plum, vern. jamun, jam; family Myrtaceae, order Myrtales
•Tectona grandis; teak, vern. sagun, sagwan; family Verbenaceae, order Lamiales
•Terminalia bellerica; belleric myrobalan, bahera, vern. bahera; family Combretaceae,
order Myrtales
•Terminalia catappa; Indian almond tree, vern. deshibadam; family Combretaceae, order
Myrtales
•Terminalia chebula; chebulic myrobalan, vern. haritaki, harar; family Combretaceae,
order Myrtales
•Terminalia coriacea, syn. T. tomentosa var. coriacea; leathery murdah, vern. tani; fam-
ily Combretaceae, order Myrtales
•Terminalia crenulata, syn. T. tomentosa var. crenulata; vern. karu maruthu, tehmbava;
family Combretaceae, order Myrtales
•Terminalia paniculata; flowering murdah, kindal, vern. kinjal; family Combretaceae,
order Myrtales
•Zizyphus jujuba, syn. Z. sativa, Z. vulgaris; vern. pitni ber, ban ber, beri; family Rham-
naceae, order Celastrales
•Zizyphus mauritiana, syn. Z. jujuba; Indian jujube, common jujube, vern. ber, hevi;
family Rhamnaceae, order Celastrales
•Zizyphus rugosa, vern. bhand, churna; family Rhamnaceae, order Celastrales
•Zizyphus xylopyra, including Z. glaberrima santapau; katber, kathber, ghont; family
Rhamnaceae, order Celastrales
The introduction of two oak tasar silkworms, Antheraea proylei and A. pernyi, has enabled
India to produce oak tasar silk. The main food plants of oak tasar silkworms belong to Quercus
species, the oaks of the family Fagaceae, order Fagales. The other food plants of temperate
tasar belong to genera like Castanopsis and Lithocarpus, of the family Fagaceae, order Fagales,
and Salix, of the family Salicaceae, order Salicales. The different species of these food plants
are (Seth, 2000b):
•Castanopsis hystrix, syn. C. rufescens; vern. katus, hingori
•Castanopsis indica; Indian chestnut, vern. bank katus, serang
•Lithocarpus dealbatus, syn. Quercus dealbata
•Quercus aegilops; valonia oak
•Quercus acutissima, syn. Q. serrata
•Quercus borealis; American red oak
•Quercus castaneaefolia; chestnut-leaved oak
•Quercus cerris; turkey oak
•Quercus coccinea; scarlet oak
•Quercus crispula
•Quercus dentata
•Quercus dilatata; green oak, moru oak, vern. moru, tilonj
•Quercus floribunda
•Quercus frainetto; Hungarian oak
•Quercus glauca; blue Japanese oak, vern. bran, siri, inai

TREES AND THEIR ECONOMIC IMPORTANCE 373
•Quercus griffithii; vern. dingim
•Quercus hispanica var. lucombeana; lucombe oak
•Quercus ilex; evergreen oak, holly or holm oak, vern. bechur, iri
•Quercus infectoria; gall oak, Dyer’s oak, vern. majuphal, mazu, muphal
•Quercus lamellosa; vern. buk, shalshi
•Quercus lanata, syn. Q. lanuginosa; woolly oak, vern. ranj, kiani
•Quercus lanceaefolia, syn. Castanopsis lanceaefolia; vern. siri, shingra
•Quercus leucotrichophora, syn. Q. incana; ban oak, gray oak, vern. ban, rin, vari, iri
•Quercus libani; Lebanon oak
•Quercus lineata; vern. phalut
•Quercus lusitanica; Lusitanian oak
•Quercus mongolica
•Quercus myrsinaefolia
•Quercus palustris; pin oak
•Quercus petraea; sessile oak
•Quercus prinus
•Quercus reticulatum; net leaf oak
•Quercus robur; English oak
•Quercus rubra
•Quercus semecarpifolia; brown oak of Himalaya, kharsu oak, vern. karshu, kharshu
•Quercus semiserrata; vern. schop
•Quercus suber; cork oak
•Quercus undulata
•Salix viminalis; English willow, osier, basket willow, vern. bibsu, kumanta
Eri silk, also known as “errandi” or “endi,” is produced by the eri silkworm Samia ricini,
syn. Philosamia ricini, Attacus ricini. It belongs to the family Saturniidae, order Lepidoptera.
Being polyphagous, it may feed on the leaves of a large number of plants (Seth, 2000c):
•Ricinus communis; castor, castor seed, vern. erandi; family Euphorbiaceae, order Eu-
phorbiales
•Ailanthus altissima, syn. A. glandulosa; ailanto, tree of Heaven, vern. barkessuru, barpat;
family Simaroubaceae, order Geraniales
•Ailanthus excelsa; vern. maharuk, barkessuru; family Simaroubaceae, order Geraniales
•Ailanthus grandis; family Simaroubaceae, order Geraniales
•Ailanthus triphysa, syn. A. malabarica; vern. guggal dhup, family Simaroubaceae, or-
der Geraniales
•Carica papaya; papaya, papaw tree, vern. papeeta; family Caricaceae, order Geraniales
•Cinnamomum cecidodaphne; family Lauraceae, order Laurales
•Coriaria nepalensis; vern. masuri, makola; family Coriariaceae, order Sapindales
•Evodia fraxinifolia; vern. payam; family Rutaceae, order Geraniales
•Gmelina arborea; gumhar, vern. gambhar, gumbhar, kambhari; family Verbenaceae, or-
der Lamiales
•Heteropanax fragrans; vern. kesseru, tarla; family Araliaceae, order Umbellales
•Hodgsonia heteroclita; vern. thebow; family Cucurbitaceae, order Passiflorales
•Jatropha curcas; physic nut, purging nut, vern. botera, bagbherenda, jangliarandi,
safedarand; family Euphorbiaceae, order Euphorbiales
•Jatropha multifida; coral plant, vern. bhotera; family Euphorbiaceae, order Euphorbiales
•Manihot esculenta, syn. M. utilissima, M. aipi, M. dulcis, M. palmata; cassava, manioc,
tapioca, vern. simul-alu; family Euphorbiaceae, order Euphorbiales

374 THE BOTANICAL REVIEW
•Ricinus virdia; family Euphorbiaceae, order Euphorbiales
•Sapium eugeniifolium; vern. korha, family Euphorbiaceae, order Euphorbiales
•Sapium sebiferum; Chinese tallow tree, vern. pippal-yang, vilayati-shisham, pahari-
shisham; family Euphorbiaceae, order Euphorbiales
•Zanthoxylum armatum, syn. Z. alatum; vern. darmar, Nepali dhaniya, tejphal, tumru;
family Rutaceae, order Geraniales
•Zanthoxylum limonella, syn. Z. budrunga, Z. rhetsa; vern. bazramani; family Rutaceae,
order Geraniales
•Zizyphus mauritiana, syn. Z. jujuba; Indian jujube, common jujube, vern. baer, ber;
family Rhamnaceae, order Rhamnales
Muga silk is produced by the muga silkworm Antheraea assama Westwood, syn. A. asamensis
Helf., A. mejankari Moore. It belongs to the phylum Arthropoda, class Insecta, order Lepi-
doptera and family Saturniidae. The muga silkworm is polyphagous (Seth, 2000d). Its primary
food plants are:
•Machilus bombycina; vern. som; family Lauraceae, order Laurales
•Litsaea monopetala, syn. L. polyantha; vern. soalu, meda, ketmarra, patoia, kakuri;
family Lauraceae, order Laurales
Its secondary food plants are:
•Actinodaphne angustifolia, syn. A. hookeri; pisa, vern. petarichawa; family Lauraceae,
order Laurales
•Cinnamomum glanduliferum; cinnamon, vern. dieng-puin-waith, dieng-sing, gonhorai,
gonhorai-arong, gonsalu, gonsarai, malligiri, marisgiri; family Lauraceae, order Laurales
•Cinnamomum obtusifolium, syn. Actinodaphne obovata; vern. patichanda, patihanda;
family Lauraceae, order Laurales
•Gmelina arboraea; gumhar, vern. bambari; family Verbenaceae, order Lamiales
•
Litsaea cubeba, syn. L. citrata; vern. mezankari, sittimbar; family Lauraceae, order Laurales
•Litsaea nitida, vern. kothalua; family Lauraceae, order Laurales
•Litsaea salicifolia; vern. dighleti, digloti; family Lauraceae, order Laurales
•Magnolia pterocarpa, syn. M. sphenocarpa; vern. panchapa; family Magnoliaceae, or-
der Magnoliales
•Michelia champaca; champak; family Magnoliaceae, order Magnoliales
•Michelia oblonga; family Magnoliaceae, order Magnoliales
•Machilus odoratissima; machilus, vern. kawala; family Lauraceae, order Laurales
•Symplocos grandiflora; family Symplocaceae, order Ebenales
•Symplocus paniculata, syn. S. crataegoides; sapphire berry, sweet leaf, vern. ludh; fam-
ily Symplocaceae, order Ebenales
•Symplocos ramosissima; vern. lodh; family Symplocaceae, order Ebenales
•Zanthoxylum armatum, syn. Z. alatum and its var. planispinum, Z. planispinum; vern.
darmar, Nepali dhaniya, tejphal, tumru; family Rutaceae, order Geraniales
•Zanthoxylum limonella, syn. Z. budrunga, Z. rhetsa; vern. bazramani; family Rutaceae,
order Geraniales
•Zizyphus jujuba, syn. Z. sativa, Z. vulgaris; vern. ber, pitni ber; family Rhamnaceae,
order Rhamnales
•Zizyphus mauritiana, syn. Z. jujuba; Indian jujube, common jujube, vern. bear, ber;
family Rhamnaceae, order Rhamnales
A large number of wild silkworms are known in nature. They, too, produce silk by feeding
on the leaves of a number of plants. However, the silk they produce is not of good quality. The

TREES AND THEIR ECONOMIC IMPORTANCE 375
food plants of these wild silkworms are: Acer campbellii, A. caudatum, Actinodaphne sikkimensis,
Anacardium occidentale, Ardisia species, Artemisia vulgaris, Bischofia javanica, Careya arbo-
rea, Cedrella serrata, C. toona, Clerodendron infortunatum, Coriaria nepalensis, Cydonia
oblonga syn. C. vulgaris, Dalbergia sissoo, Dillenia indica, D. pentagyna syn. D. pentagynia,
Emblica officinalis syn. Phyllanthus emblica, Eugenia fruiticosa, Glochidion hohenackeri syn.
G. lanceolarium, G. velutinum, Juglans rigia, Lagerstroemia speciosa syn. L. flos reginae,
Lannea coromandelica syn. Odina wodier, Leucosceptrum canum, Litsaea glutinosa syn.
L. sebifera, Lyonia ovalifolia syn. Pieris ovalifolia, Machilus odoratissima, Mangifera indica,
Melastoma malabathricum, Meyna laxiflora syn. Vangueria spinosa, Microcos paniculata syn.
Grewia microcos, Mimusops elengi, Mitragyna rotundifolia syn. Stephegyne diversifolia, Oci-
mum spp., Phyllanthus lanceolaria, Prunus cerasoides syn. P. puddum, Pterospermum semi-
sagittatum, Pyrus communis, P. pashia, Salix babylonica, S. tetrasperma, Sapium insigne,
Schleichera oleosa, syn. S. trijuga, Symplocos paniculata, syn. S. crataegoides, S. racemosa,
Syzygium cuminii syn. Eugenia jambolana, Terminalia alata syn. T. tomentosa, Turpinia
nepalensis, T. pomifera, Wendlandia thyrsoidea syn. W. notonia, Zanthoxylum acanthopodium
and Z. armatum syn. Z. alatum (Seth, 2000e).
IV. Conclusions
As discussed above, trees are of great importance to people, not only economically and
ecologically but also ornamentally and bioaesthetically. Because trees meet the needs of hu-
mans, the primary objective of any afforestation, biodiversity, ecodevelopment, bioaesthetic or
landscape plan must be both to protect native tree–growing areas from further destruction and
to plant trees in large areas. For any society, planting and care of trees serve as important
endeavors and symbolize hope for the future. Multipurpose trees and shrubs have the capacity
to provide for a variety of end uses while reversing the process of land degradation.
Most of our environmental problems can be solved to a great extent if we grow more trees,
especially in urbanized localities and cities. Because people in different parts of the world have
become aware of the needs of trees and forests, many countries have started celebrating annual
“Forest Festivals” or “Tree Festivals” or “Greening Weeks” or “Arbor Days.” In India, too, tree
planting has been adopted as a national policy. The first successful tree-planting week was
celebrated in Delhi in July 1947, with the participation of national leaders like Jawaharlal
Nehru, Rajendra Prasad and Abdul Kalam Azad, among many others (Randhawa, 1961, 1965–
1983). In 1950 the celebration was renamed “Vana Mahotsava” (Grand Festival of Forests [or
Trees]) (Seth et al., 1962).
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