A survey of succulent mallows of the mallow family (Malvaceae)

Abstract

The mallow family (Malvaceae) is large but only a relatively few species exhibit pachycaul succulence (bottle trees with fat stems) or have succulent leaves. This article surveys succulence in this family belong to the genera Adansonia, Brachychiton, Cavanillesia, Ceiba, Megistostegium, Pseudobombax and Sterculia.

Full text

135CactusWorld Vol. 39 (2)
Introduction
The mallow family, the Malvaceae, has a worldwide
distribution with around 4,200 species in about 240
genera (Stevens, 2017). In the first edition of The
Illustrated Handbook of Succulent Plants, succulent
plants of this alliance were treated in two separate
families: the Bombacaceae (Walker, 2002) and the
Sterculiaceae (Forster & Guymer, 2002). However, as
a result of recent molecular studies the Malvaceae have
been expanded to encompass three former separate
families: the Bombacaceae, Tiliaceae and Sterculiaceae.
Consequently the succulent plants surveyed here will
all be treated as members of the single family, the
Malvaceae, in the second edition of The Illustrated
Handbook of Succulent Plants (Walker, 2021)
The most familiar representatives of this family are the
garden plants Hibiscus, hollyhock (Althaea) and
A survey of succulents of the
mallow family (Malvaceae)
Colin C Walker
The mallow family (Malvaceae) is large but only relatively few species exhibit either pachycaul
succulence (bottle trees with fat stems) or have succulent leaves. This article surveys
succulence in this family. Photography as indicated.
Fig. 1 (below) Baobab fruit (from Alpino, 3rd ed., 1735)
Fig. 2 (top right) Adansonia digitata in leaf at Sua Pan,
Botswana (Photo: Ralph Stutchbury)
Fig. 3 (bottom right) Adansonia digitata looking more majestic
in the leafless resting state in SE Zimbabwe
(Photo: Ralph Stutchbury)

136 CactusWorld Vol. 39 (2)
mallow (Lavatera). By far the most economically
important genus is cotton (Gossypium) followed by
cocoa/chocolate (Theobroma cacoa). The family
occurs in most of the world, except for the very cold
regions and is particularly abundant in tropical South
America. Just a few, perhaps 35 species, have the
pachycaul swollen habit of succulent bottle trees, or in
the case of Megistostegium, exhibit leaf succulence.
Succulent mallow species occur naturally in central
and South America, Africa, Madagascar and Australia.
The baobabs of the genus Adansonia are the most
famous of these but succulents also occur in the less
familiar genera Brachychiton,Cavanillesia, Ceiba,
Megistostegium, Pseudobombax and Sterculia.
Adansonia
This is the genus of the baobab of sub-Saharan Africa
or the boab in Australia, with its enormously swollen
outline that has given rise to the nickname of ‘Africa’s
upside-down tree’. There has been much speculation
as to the age of baobabs. Recent radiocarbon dating of
trees has given ranges of 1,100 to 1,600 years old.
Therefore postulated ages in excess of 2,000 years for
larger trees do not seem unreasonable since adult trees
exhibit slow growth rates (Wickens & Lowe, 2008).
Baobabs have been known for many centuries
(perhaps millennia) and the early Egyptians were
apparently aware of them. However, the first
published description of the baobab appeared in 1592
in a book on Egyptian plants entitled De Plantis
Aegypti Liber in which the Italian botanist and doctor
Prospero Alpino (1553–1617) described and
illustrated the fruit which he called the bahobab. This
is the origin of the familiar common name (Alpino,
1592, Fig. 1). Alpino was aware of the fruit that was for
sale in Egyptian markets but he was unable to describe
the tree since it is not native to Egypt. The French
botanist, Michel Adanson, was the first to describe the
tree and its large flowers, which he called the baobab
based on Alpino’s name. Adanson made detailed
observations of baobabs during his visit to Senegal
(1748–1753) (Adanson, 1761). Based on Adanson’s
work, Carl Linnaeus commemorated him in the
generic name Adansonia.
The genus currently consists of eight species: one in
Africa, six in Madagascar and one in north-western
Australia (Baum, 1995b; Petignat & Jasper, 2015). This
remarkable disjunct distribution across two continents
is considered to be the result of long-distance oceanic
dispersal of fruit which originated on the African
mainland. This dispersal was followed by radiation
and speciation, notably in Madagascar where the
maximum species diversity currently resides (Wickens
& Lowe, 2008). Adansonia digitata (Figs. 2 & 3) has
the widest distribution occurring in much of
Fig. 4 Flower of A. digitata (Photo: Ralph Stutchbury)
Fig. 5 Adansonia za in the leafless resting state,
Tsimanampetsotsa Nature Reserve, Madagascar
(Photo: Al Laius)

137CactusWorld Vol. 39 (2)
sub-Saharan Africa. Its white pendulous flowers last
for just 24 hours; they open in the evening and petals
evert rapidly to reveal the anthers (the male parts),
which are initially hidden by the long petals (Fig. 4).
For A. digitata, authenticated records exist for both bat
and bushbaby pollination, although the latter animal
has a relatively restricted distribution compared with
the baobab. The Madagascan and Australian species
are pollinated by long-tongued hawkmoths, fruit bats
or lemurs (Baum, 1995a).
The six Madagascan species occur in the arid north,
west and south-west of the island. In terms of
distribution, these range from the widespread A. za
(Fig. 5), to A. rubrostipa (Fig. 6), distributed along the
west coast, to the highly localised and hence
endangered A. perrieri, which is known from just a few
sites in the extreme north. The Australian A. gregorii
occurs in the north of Western Australia and in north-
western Northern Territory (Petignat & Jasper, 2015).
Fig. 6 Adansonia rubrostipa in fruit between Ifaty and Tulear, Madagascar (Photo: Al Laius)
Fig. 7 Fruit of A. digitata, Nwanedi, Limpopo Province,
South Africa (Photo: Gideon Smith)
Fig. 8 Fruit of A. za, which is especially variable, can be up to
30cm long and 15cm diameter. The surface layer (pericarp) is
thick and tough (Photo: Al Laius)

138 CactusWorld Vol. 39 (2)
The baobabs are renowned for their pachycaul
appearance with squat or bottle-shaped stems up to
30m or more tall, up to 5m or more in diameter and up
to 16m or more in circumference, with well branched
crowns. The deciduous leaves of baobabs are palmate
with up to nine leaflets. Flowers are pendulous in
A. digitata but erect in the other species. Petals are
white, yellow or red. Fruits are dry, large and very
variable in shape (Figs. 7 & 8), ranging from globose to
cylindrical with a thick, woody outer layer (the
pericarp) and with the many seeds embedded in a
white spongy pulp.
All parts of the tree have some economic or cultural
importance, notably in Africa but also to a lesser extent
in Madagascar and Australia. The hollow trunks have
been used for diverse purposes, ranging from shelter
and storage to such unusual uses as being fitted with a
flush toilet or being used as a prison as in the case of
the Derby Prison Tree in Australia. Other parts of the
plant have also been used by humans. The wood is
spongy and very moist and hence unsuitable for
timber but does have some constructional uses, for
example for lightweight canoes and as roofing
material. Fresh leaves, and especially the fruits, are a
rich source of vitamin C (ascorbic acid) and tartaric
acid and are widely used to produce refreshing
lemonade-like drinks, or more recently, baobab
smoothies (Figs. 9 & 10). Adansonia digitata is
cultivated outside of its natural
range in Africa and this appears to
account for records in India,
northern Madagascar and
southwestern Arabia (Wickens &
Lowe, 2008). In temperate latitudes
where greenhouse cultivation is
required because these trees are
frost-sensitive, baobabs do not
make attractive specimens, since
the appealing pachycaul habit of the
bulky trunk of mature specimens
takes a long time to develop.
The literature on baobabs is now
remarkably extensive for such a
Fig. 9 (top left) Baobab bar at the Eden
Project, Cornwall
(Photo: Colin Walker)
Fig. 10 (middle left) The author enjoying
a baobab smoothie at the Eden Project
(Photo: Marjorie Thorburn)
Fig. 11 (bottom left) Brachychiton
rupestris in cultivation at Sydney Botanic
Garden (Photo: Colin Walker)

139CactusWorld Vol. 39 (2)
small genus and includes the
highly recommended and well-
illustrated books by Pakenham
(2004), Watson (2007), Stutchbury
(2013) and Petignat & Jasper
(2015).
Brachychiton
This is a genus of about 30 species,
all of which are endemic to
Australia apart from one endemic
to Papua New Guinea and a
second species shared with Papua
New Guinea. Just three species
have well-developed pachycaul
bottle-shaped stems (Kapitany,
2007, 2015), of which Brachychiton rupestris develops
the largest and broadest stem of the genus (Fig. 11).
All succulent brachychitons known as ‘Bottle Trees’ in
Australia were previously classified in the separate but
now obsolete family Sterculiaceae, along with Sterculia
(Forster & Guymer, 2002). Brachychiton was named
from the Greek ‘brachys’ meaning ‘short’ and ‘chiton’
meaning ‘covering’, for the short covering around
the seed.
Brachychiton rupestris is a mostly evergreen tree up to
25m tall, always developing a swollen trunk that is
bottle-shaped to 3.5m diameter at breast-height with
dark grey, deeply fissured and tessellated bark. Shorter
trees often develop the most disproportionately broad
trunks (Kapitany, 2015). The leaves are crowded at the
branch tips, are shiny above but glaucous below and
linear-lanceolate to lanceolate in shape. This species
can be semi-deciduous in some climates with leaves
not falling every year and not necessarily from all the
branches (Kapitany, 2007). It is endemic to the state of
Queensland, where it grows inland from the coast in
drier areas and is most commonly found in semi-
evergreen vine-thicket and in Brigalow scrub
dominated by the wattle Acacia harpophylla. It was
named rupestris for its ‘often rocky habitats’.
Populations of B. rupestris are sharply declining over
its range, in particular through a lack of natural
regeneration (Kapitany, 2015). It is widely grown in
Fig. 12 (top right) Cavanillesia
tuberculata (but more likely C. arborea)
from the Brazilian Caatinga (desert
vegetation). (From Kerner von Marilaun
& Oliver, 1894–1895)
Fig. 13 (bottom right) Cavanillesia
arborea North of Bom Jesus de Lapa,
Brazil. Notice that the maximum stem
diameter is a good way up the stem and
not at its base (Photo: Graham Charles)

140 CactusWorld Vol. 39 (2)
parks and gardens in Australia. The stems and leaves
are sometimes used for drought-fodder for cattle and
have the vernacular names of ‘Bottle-Tree’,
‘Queensland Bottle Tree’ and ‘Narrow-Leaved Bottle
Tree’ (Forster & Guymer, 2002).
Cavanillesia
This is a genus of just five species with enormously
swollen non-prickly pachycaul stems. They occur
naturally in tropical central and southern America,
ranging from Panama to Brazil. The genus was first
described in 1794 and named for Antonio J Cavanilles
(1745–1804), a Spanish clergyman and botanist in
Paris and Madrid (Walker, 2002). These South
American bottle trees have often featured in early
literature because of their unusually shaped stems,
often with their greatest stem diameter well above
ground level (Fig. 12).
Cavanillesia arborea is the most familiar species,
especially to cactus hunters in Brazil where it is
endemic. Trees of this species resemble the baobab
because of their large size, architectural appeal of the
trunks and canopy and generally long lifespan (Figs. 13
& 14). This is a classic example of convergent
evolution, where the same plant growth form has
evolved in tandem in two different continents, in this
case South America and Africa. Cavanillesia arborea
can grow to over 35m tall in fertile soils. Eric
Werdermann, an early German cactus explorer of the
1930s in Brazil, wrote that “we shall never forget our
trip through the fairy land of ‘bottle trees’ (Cavanillesia
Fig. 14 Another specimen of C. arborea with prominent stem
scars (Photo: Graham Charles)
Fig. 15 Ceiba speciosa in the leafless resting state in cultivation
at The Huntington Botanical Gardens, San Marino, California
(Photo: John Trager)

141CactusWorld Vol. 39 (2)
arborea), which arose like giants out of [the] distant
past in the confusion of dry branches of low trees and
underbush. However majestically they rounded out
their circumference, just as little resistance did their
spongy soft wood offer to a scratching thumb nail”
(Werdermann, 1942). A particularly gigantean
specimen is wonderfully illustrated in a later book
entitled Cacti in Brazil (Herm et al, 2001). I estimate
that this specimen has a stem about 3.5m diameter at
its maximum girth and is around 7.5m tall up to the
point where it starts to taper quite distinctly into the
crown of branches. Its flowers produce a disagreeable
odour and large amounts of pollen. Again, similarly to
the baobab, the flowers demonstrate nocturnal
opening and are probably pollinated by bats. Its seeds
are winged and wind-dispersed (Melo Júnior et al, 2015).
Cavanillesia chicamochae is a relatively recent
discovery (Fernández-Alonso, 2003) named for the
Chicamocha River Canyon in Colombia where it is
endemic. It forms trees 4–6m tall with a very thick
fusiform trunk at the base up to 1m in diameter, often
with roots exposed as small stilts; stems and branches
are often irregularly shaped, sometimes curved
downwards, generally with conspicuous scars or
transverse bands. This species is the smallest tree and
also the most localised species in the genus, being
known from a single river valley, where it has the
vernacular name of ‘Barrigón’ which refers to the
barrel-shaped trunk. Occasionally the trunk is cut and
used for raft making. Goats are also recorded as being
a threat, since they consume bark,
young branches and seedlings
(Fernández-Alonso, 2003).
Of the three other species of
Cavanillesia, C. platanifolia is the
most northerly and probably has
the widest distribution ranging
from Panama to Peru. It forms
trees up to 30m tall that are
somewhat swollen near the base
with an open crown. Cavanillesia
hylogeiton (Peru) and C. umbellata
(Peru, possibly Bolivia and Brazil)
are relatively unknown bottle trees.
The genus has received little
attention and is in need of revision.
Fig. 16 (top) Closer view showing the
stem with prickles of C. speciosa
(Photo: John Trager)
Fig. 17 (bottom) Close-up of the stem
prickles of C. speciosa
(Photo: John Trager)

142 CactusWorld Vol. 39 (2)
Like the baobabs, cavanillesias do not make attractive
pot plants or greenhouse subjects because the
pachycaul habit is not well developed in small, young
specimens. Hence these plants are rarely cultivated in
temperate climates.
Ceiba
This is another small American genus of about 18
species, which now includes those species formerly
separated in the genus Chorisia. Only six species are
considered to have swollen, pachycaul, aculeate
(prickly) stems currently of interest to succulent plant
enthusiasts (Walker, 2021). In the latest revision of
Ceiba, Gibbs & Semir (2003) accepted seven distinct
species in what they referred to as the “Ceiba insignis
aggregate species”. Of the six pachycaul species,
C. chodatii,C. speciosa and C. ventricosa belong to this
C. insignis aggregate species complex, whereas
C. boliviana,C. glaziovii and C. rubriflora are more
Fig. 18 (left) White-flowered form of C. speciosa
(Photo: John Trager)
Fig. 19 (below) Flower of C. speciosa ‘Majestic Beauty’, a
selection made by Monrovia Nursery, Azusa, California
(Photo: John Trager)

143CactusWorld Vol. 39 (2)
distinct and distantly related to this complex. Ceiba
insignis in the narrow sense of Gibbs & Semir (2003)
does not have swollen stems and so is no longer
considered to be a pachycaul succulent. The name
Ceiba is derived from the Spanish ‘ceiba’ describing
some sort of American cotton tree.
Three species of Ceiba occur in Mexico and Central
America and 14 species are distributed in South
America. Ceiba pentandra (a non-succulent) is the
only species which extends outside of South to Central
America and the Caribbean islands, occurring in West
Africa, where it is probably native and also in India,
South East Asia and the Pacific, to which areas it was
most likely introduced by humans (Gibbs & Semir,
2003). Ceiba is of economic importance as ‘Kapok’ or
‘Silk-Cotton Tree’, the source of kapok, a lightweight,
water-resistant fibre used in pillows, etc.
Of the six pachycaul species only C. speciosa is widely
grown outdoors in tropical or subtropical countries or
those with Mediterranean-type climates. It is still most
often encountered labelled Chorisia speciosa. Other
species of the Ceiba insignis alliance are apparently
only rarely cultivated, if at all, in Europe and the USA,
but an appraisal of much of the cultivated material is
yet to be undertaken.
Ceiba speciosa has a very wide distribution in South
America: west, north-east and south-east Brazil,
northern Argentina, Paraguay, Bolivia, South and
central Peru. It occurs in dry semi-deciduous
woodland, wet forest and humid river valleys. It is also
widely cultivated in Argentina and Brazil as
an ornamental.
This species grows as trees up to 20m tall with a
spreading crown. The pachycaul trunk is immensely
Fig. 20 Ceiba rubriflora in leafless state in the dry season, near
Iuiú, State of Bahia, Brazil (Photo: Graham Charles)
Fig. 21 Ceiba rubriflora with buds, flowers and very prickly
branches, near Iuiú, State of Bahia, Brazil
(Photo: Graham Charles)

144 CactusWorld Vol. 39 (2)
swollen, up to 2m diameter
at the widest part (Fig. 15),
generally covered with
large, cone-like woody
prickles (Figs. 16 & 17). Its
leaves are digitate (hand-
like) with 5–7 leaflets. The
flowers (Figs. 18 & 19) are
relatively large, hence
conspicuous, very attractive
and come in a very wide
range of colours from
crimson or pink to yellow
or white with or without
chestnut-brown blotches in
the throat.
Ceiba speciosa is a readily
available and easily-grown
pachycaul. In succulent
plant collections this makes
an attractive species with
its prominently prickly
pachycaul stem and
spectacular flowers. It is
frequently planted in parks
and gardens in frost-free
climates around the world
for its interesting growth
form and free-flowering
nature. De Vosjoli (2004)
reports that “in warmer
areas of the US, these
impressive trees with
green trunks and giant
thorns make outstanding
landscape specimens.
Several forms exist,
including a thornless dark
pink-flowered form”.
These trees can also make
“outstanding tropical
bonsai specimens but
require heat”.
Ceiba rubriflora is the most
recently described species
(Figs. 20 & 21). It is
characterised by its
Fig. 22 Megistostegium perrieri,
Cap Sainte Marie, the southern
tip of Madagascar
(Photo: Al Laius)
Fig. 23 Pseudobombax ellipticum (Photo: Tina Wardhaugh)

145CactusWorld Vol. 39 (2)
relatively small flowers with deep
red petals and stamens which are
unique amongst the Brazilian
species of Ceiba and is one of five
species recorded for the State of
Bahia. Its closest relatives appear to
be the non-pachycaul C. erianthos
and C. schottii. Plants flower
during the dry season in July and
August when leafless (Fig. 20) and
set fruit in September. This is
possibly the most localised of all
the Ceiba species. Its conservation
status was assessed as Critically
Endangered since it occurs in an
area estimated to be less than
100km2, where it grows in severely
fragmented and declining
habitat (Carvalho-Sobrinho &
Queiroz, 2008).
Megistostegium
This is an endemic Madagascan
genus consisting of just three
species of which two have succ-
ulent leaves whilst the third,
M. nodulosum, the most wide-
spread, is modestly pachycaul but
with thin non-succulent leaves
(Koopman, 2011). These plants are
prostrate or erect shrubs or trees to
8m tall. The name is derived from
‘megisto-‘ meaning ‘very large’ and
‘-stegium’, for the large gynoecium
or the female part of the flower. These plants are
restricted to the xeric, deciduous spiny forest of south-
west Madagascar and associated coastline.
Megistostegium perrieri is a sturdy, prostrate subshrub
up to 1m tall with terminal clusters of leaves on the
branches. Its leaves are relatively large, succulent and
covered with soft, tomentose stellate (star-shaped)
hairs. The maroon flowers are pendant and attractive
(Fig. 22; Rauh, 1995). This species is very localised,
being restricted to the wind-swept calcareous coastline
of the Mahafaly plateau at Cap Sainte Marie at the very
southern tip of Madagascar. The short stature of this
plant is partly in response to the constant wind
blowing off the Mozambique Channel. When plants
are growing in sheltered, rocky outcrops on cliffs they
grow taller. The limited distribution of this species at
only two locations gives rise to a conservation status of
Endangered. A particular threat appears to be the
absence of an effective pollinator (Koopman, 2011).
This species is possibly not currently in cultivation.
Pseudobombax
This is yet another small American genus of about 30
species that until 1943 was included in Bombax, hence
the name meaning ‘false Bombax’. They are
distributed in neotropical America from Mexico to
northern Argentina, but two-thirds of the species
occur in Brazil, forming a centre of diversity. The
genus is more diverse in areas subject to a long dry
season with xerophytic vegetation such as the caatinga
of north-east Brazil and the Venezuelan llanos
Fig. 24 Pseudobombax ellipticum in cultivation at The Huntington Botanical Gardens,
San Marino, California. Notice that with free root room and hence presumably reasonably
fast growth, this specimen has lost most of the appealing pachycaul growth form
(Photo: John Trager)

146 CactusWorld Vol. 39 (2)
(Carvalho-Sobrinho & Queiroz, 2011). Plants have
deciduous foliage during the flowering season, an
adaptation to bat pollination (chiropterophily) and
their preference for habitats subject to a long dry
season when the plants mostly flower.
Pseudobombax is characterised by trunks with often
irregular greenish stripes, digitate leaves clustered at
the branch apices, leaflets not jointed to the petiole
(leaf stalk), filaments (of the stamens) joined in a tube
in the flower and fruits that are woody capsules with
abundant kapok (dense soft fibres) in which the seeds
are embedded. Absence of woody stem prickles and
leaflets not jointed to the petiole are considered to be
key features of Pseudobombax (Carvalho-Sobrinho
et al, 2016).
Pseudobombax ellipticum is widely distributed,
naturalised and cultivated in central America and the
Caribbean and is by far the most commonly
encountered species in cultivation in Europe and the
USA. It forms an attractive basally-swollen pachycaul
with contrasting striped bark and large digitate leaves,
particularly suitable for pot plant culture when young,
especially since it is readily available commercially.
Specimens given bonsai treatment are particularly
appealing (Fig. 23). It can also be grown outdoors in
warmer temperate zones (Fig. 24), but with rapid
growth the pachycaul stems of young specimens can
quickly grow into non-pachycaul trees up to 10m tall
(De Vosjoli, 2004). Its flowers are attractive, the most
prominent feature of which is the large number (up to
350) of stamens giving the flower the look of a loose
shaving-brush, with the narrow petals recurved or
curled (Fig. 25).
Apparently the only other species currently in general
cultivation is Pseudobombax palmeri (Fig. 26). As
Bombax palmeri it was distributed by the ISI in 1970 as
seedlings (ISI 631 & 632) raised from seed collected by
Myron Kimnach in 1969 in Sonora, Mexico (Anon,
1970). It was described as forming “a small tree with a
grotesquely swollen, reddish trunk that usually juts
forth from cliffs. Its leaves are large and hand-shaped,
and its flowers resemble those of waterlilies. It makes
an excellent pot-plant, whereupon its stem becomes
globular and nearly as thick as the plant is high”. The
specimen shown in Fig. 26 is over 50 years old from
Fig. 25 Flowers of P. ellipticum in cultivation at the Huntington Botanical Gardens (Photo: John Trager)

147CactusWorld Vol. 39 (2)
seed from another Kimnach collection from Jalisco in
1970. This evidence therefore suggests that as a pot-
grown specimen it exhibits a very slow growth rate,
which contrasts with the significantly faster growth
rate reported for P. ellipticum.
Sterculia
Sterculia is a large genus of ± 150 species with a
pantropical distribution, few of which have a well-
developed pachycaul stem and only four species were
considered to be succulent by Forster & Guymer,
(2002). It was formerly placed in the separate and now
obsolete family Sterculiaceae. Named after Sterculius,
the Roman deity of dung, from the Latin ‘stercus’
meaning ‘dung’, for the unpleasantly smelling flowers
of some taxa.
Sterculia africana (Fig. 27) has an exceedingly wide
distribution, probably the widest range of any species
in the genus, occurring throughout much of tropical
and north-east Africa from the Caprivi Strip in north-
east Namibia, then northwards into southern Arabia
including Socotra. It grows into erect, pachycaul
deciduous trees 5–12m tall with a main trunk to
1m diameter. The bark is silvery-grey, brown or white,
peeling in papery flakes revealing an attractive pink
surface. The branches are brittle and semi-succulent.
Its leaves are up to 15cm long and across, broadly ovate
to almost circular with up to five lobes and are
crowded at the branch tips. It sheds its leaves during
the dry season and comes into flower before the leaves
reappear at the start of the rainy season. This species
is recommended for cultivation in South Africa and
Namibia in ‘waterwise gardening’ in Bushveld and
Namib Desert gardens, but the growth rate is reported
to be slow under such conditions (van Jaarsveld, 2010).
It sometimes has the vernacular name of
‘Mopopaja Tree’.
ACKNOWLEDGEMENTS:
Graham Charles, Al Laius, Gideon Smith, Ralph Stutchbury,
Marjorie Thorburn, John Trager and Tina Wardhaugh are thanked
for the use of their excellent photos. I am especially grateful to John
for specifically photographing the Huntington’s specimen of the
very rare Pseudobombax palmeri at my request. Graham Charles,
Urs Eggli, Al Laius and John Trager provided guidance and advice.
My wife Marjorie read and commented on an earlier version
of this article.
Fig. 26 Pseudobombax palmeri in cultivation at the Huntington Botanical Gardens, San Marino, California. HBG 25243. Raised from
seed collected on the Huntington expedition to Mexico in November, 1970. Boutin & Kimnach 2959, Sierra de Minatlán, Jalisco, Mexico,
on the road to Hacenadero beyond El Chante, 1,219m (Photo: John Trager)

148 CactusWorld Vol. 39 (2)
LITERATURE:
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81–87.
Alpino, P (1592) De Plantis Aegypti liber. Franciscum de Franciscis
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Baum, D A (1995a) The comparative pollination and floral biology
of baobabs (Adansonia – Bombacaceae). Ann. Missouri Bot.
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Mota, A C, & Baum, D A (2016) Revisiting the phylogeny of
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Fig. 27 Sterculia africana on Socotra (Photo: Al Laius)
Dr Colin C Walker, School of Environment, Earth & Ecosystem Sciences, The Open University, Milton Keynes, MK7 6AA, England.
Email: c.walker702@btinternet.com Layout by Gregory Bulmer