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The comparative morphology and anatomy of Dioscorea sylvatica Eckl. from Natal and the Transvaal
Abstract
The morphology of Dioscorea sylvatica from Natal and the hills in the Lydenburg district of the Transvaal is described, as well as the anatomy of the leaf and stem. Differences were noticed between the Natal and Lydenberg types which are inconsistent with Burkill's classification of the species. From the differences it is suggested that the Lydenberg type be designated as D. sylvatica subspecies lydenbergensis subsp. nov.
... Dioscorea is included in the monocot family Dioscoreaceae (Blunden et al., 1971) and its rhizomes have been used for treating a wide range of conditions including allergy, dermopathy, some cancers, diabetes mellitus, inflammation, lipoperoxidation, renal infections, and rheumatoid arthritis (Tewtrakul & Itharat, 2006;Wang et al., 2007;Zhang et al., 2009;Zhu et al., 2010;Ghosh et al., 2012). The dicot genus Corydalis belongs to the poppy family Papaveraceae s.l. ...
... Leaf and stem anatomical characters of Dioscorea sylvatica Eckl. have been reported previously using a wax embedding method and the status of D. sylvatica revised to a subspecies (Blunden et al., 1971). Two species of Dioscorea, D. floribunda and D. spiculiflora, have been subjects for tuber anatomy studies (Martin & Ortiz, 1963). ...
Resin embedding methodology was evaluated for authentic herbal medicinal identification using tubers or rhizomes of Corydalis and Dioscorea in the current study. Dealing with hard herbal drug materials for anatomical works can be challenging, but using the resin embedding approach makes easier to dissect the herbal drugs. Corydalis and Dioscorea tubers are secondary organs considering the fact that they have main roots as well as the tubers or rhizomes. The tuber anatomical characters are not complicated; however, the characteristic anatomical features can be useful as identification tools for those well-known Oriental herbal medicines.
... A similar approach should be considered for other potential early leaf records if used for calibration analyses (e.g., Mehrotra and Shukla 2019). Leaves of extant Dioscorea have been reported to have diacytic, tetracytic, paracytic, and anomocytic stomata and epidermal cells without strong sinuous anticlinal walls (e.g., Blunden et al. 1971;Ayensu 1972;Abdulrahaman et al. 2009). Similar leaf shape and venation are seen in Smilax (Smilacaceae). ...
... Wilkin (2001Wilkin ( , 2009 does not subdivide this species into varieties and comments that further studies are needed to investigate the delimitation of D. sylvatica from D. elephantipes, "as they appear to differ only in leaf shape". Tubers are variable in shape and outline (see Blunden & al. 1971 Testudinaria multiflora Marloth (1913) Testudinaria sylvatica var. multiflora (Marloth) G. D. Rowley (1973); incl. ...
... Plant anatomy studies of fresh materials have played an important historical role in the classification and identification of plants [15]. Nevertheless, for the species of Dioscorea, only a very few anatomical studies have been conducted [3, [16][17][18][19][20][21][22]. The only comprehensive work on the anatomy of Dioscorea was published by Ayensu in 1972 [20]. ...
The edible tubers from different species of Dioscorea are a major source of food and nutrition for millions of people. Some of the species are medicinally important but others are toxic. The genus consists of about 630 species of almost wholly dioecious plants, many of them poorly characterized. The taxonomy of Dioscorea is confusing and identification of the species is generally problematic. There are no adequate anatomical studies available for most of the species. This study is aimed to fill this gap and provides a detailed investigation of the anatomy and micro-morphology of the rhizomes and tubers of five different species of Dioscorea, namely D. balcanica, D. bulbifera, D. polystachya, D. rotundata and D. villosa. The primary features that can help in distinguishing the species include the nature of periderm, presence or absence of pericyclic sclereids, lignification in the phloem, types of calcium oxa-late crystals and features of starch grains. The descriptions are supported with images of bright-field and scanning electron microscopy for better understanding of these species. The diagnostic key of anatomical features included in this paper can help distinguish the investigated species unambiguously. Additionally, HPTLC analyses of authentic and commercial samples of the five species are described.
... Plant anatomy studies of fresh materials have played an important historical role in the classification and identification of plants [15]. Nevertheless, for the species of Dioscorea, only a very few anatomical studies have been conducted [3, [16][17][18][19][20][21][22]. The only comprehensive work on the anatomy of Dioscorea was published by Ayensu in 1972 [20]. ...
The edible tubers from different species of Dioscorea are a major source of food and nutrition for millions of people. Some of the species are medicinally important but others are toxic. The genus consists of about 630 species of almost wholly dioecious plants, many of them poorly characterized. The taxonomy of Dioscorea is confusing and identification of the species is generally problematic. There are no adequate anatomical studies available for most of the species. This study is aimed to fill this gap and provides a detailed investigation of the anatomy and micro-morphology of the rhizomes and tubers of five different species of Dioscorea, namely D. balcanica, D. bulbifera, D. polystachya, D. rotundata and D. villosa. The primary features that can help in distinguishing the species include the nature of periderm, presence or absence of pericyclic sclereids, lignification in the phloem, types of calcium oxalate crystals and features of starch grains. The descriptions are supported with images of bright-field and scanning electron microscopy for better understanding of these species. The diagnostic key of anatomical features included in this paper can help distinguish the investigated species unambiguously. Additionally, HPTLC analyses of authentic and commercial samples of the five species are described.
Background
Diosgenin, mainly extracted from wild diosgenin-contained Dioscorea species, is a well-known starting material of steroidal and contraceptive drugs. However, due to large market demand and increasingly ecological damage, wild Dioscorea species resources available have been gradually declining. Therefore, identification of new potential ecological distribution of diosgenin-contained Dioscorea species is necessary for diosgenin production.
Methods
In this study, a large occurrence dataset (1808 data points) of diosgenin-contained Dioscorea species was obtained from Eastern Asia, Southern North America and Southern Africa. Along with the data for six critical environmental parameters and one soil factor, Geographic Information System for Global Medicinal Plant was applied to predict the potential suitable distribution of Dioscorea species.
Results
The results showed that the potential distribution of these Dioscorea species covered a wide field, and that new ecological suitability areas were mainly distributed in the central region of South America, the southern part of the European and coastal region of Oceania. Jackknife test indicated that annual precipitation and annual mean radiation were the important climatic factors controlling the distribution of Dioscorea species.
Conclusions
The suitable areas and critical climatic factors will serve as a useful guide for diosgenin-contained Dioscorea species conservation and cultivation in ecological suitable areas.
Electronic supplementary material
The online version of this article (10.1186/s13020-018-0215-8) contains supplementary material, which is available to authorized users.
Certain developmental and anatomical studies on D. sansibarensis Pax are briefly reported. (1) Stem diameter, internodal length, vessel diameter, distribution and number of vascular bundles in internodes (from base to apex) are determined. There is no correlation between vessel size and stem diameter. Cut stems left in water develop tyloses. (2) Roots are all polyarch. The development and structure of the vessels are discussed. Xylem and phloem differentiation in the root tip is determined. A central meristem at the root apex gives rise to the different tissues in the root. Raphide development in root cortex is traced. (3) Both alternate and opposite leaf arrangements occur, sometimes on the same plant, and there is a correlation between stem thickness and leaf arrangement. During leaf development the lamina length exceeds the width, but the two dimensions reach their maximum size at the same time. The acuminate leaf-tip matures before the rest of the leaf. Stomatal development is traced.
The compilation of new data on stomatal ontogeny from the literature and the finding of a rather unknown type inMarcgravia have shown the need of a new classification of the ontogenetic types of stomata. Pant (1965) recognized 10 main types; this
number is now enlarged to 26 and a modified terminology is chosen. From the name of each type not only the ontogenetical pattern
but also the morphological nature of the adult stoma can be deduced. Thus the gap between morphological and ontogenetical
classifications has been bridged.
Two important differences from Pant’s classification and definitions are introduced.
In this classification any other new type can be included; all the possibilities for the introduction of supplementary data
are left open.
Notes on the anatomy of the Dioscoreaceae
- Ayensu
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- E S Ayensu
AYENSU, E. S., 1971. Anatomy of the Monocotyledons, 6, Dioscoreales. Oxford: Clarendon Press. BURKILL, I. H., 1952. Testudinaria as a section of the genus Dioscorea,Jl S. Afr. Bot., 18: 177-191.
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A list of plants found in the district of Uitenhage, between the months of July, 1829, and February, 1830, together with a description of some new species
- Ecklon
Dioscorineae (Testudinaria)
- Kunth
Testudinaria-the elephant's foot
- Rowley