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This species is accepted, and its native range is Madagascar.
A specimen from Kew's Herbarium

[KBu]

Odile Weber, Wilkin, P., & Rakotonasolo, F. (2005). A New Species of Edible Yam (Dioscorea L.) from Western Madagascar. Kew Bulletin, 60(2), 283-291. Retrieved from http://www.jstor.org/stable/4110938

Conservation
Data deficient (IUCN 2001). The herbarium specimens cited above suggest that it is relatively abundant at Bemaraha.
Distribution
Western Madagascar from Ampandandrava to the Ankara region West of Maevatanana. Most collections to date have been made from the Tsingy de Bemaraha region in west- central Madagascar.
Ecology
Deciduous forest, often on limestone, between 100 and 900 m in altitude. Often flowering early in the rainy season in October and November, sometimes before the leaf blades are fully expanded, and fruiting thereafter.
Morphology General Habit
A twining dioecious vine to about 10 m, stems annual from a fleshy tuber
Morphology General Indumentum
Indumentum of simple hairs, 0.3 - 1.9 mm long, straight to crispate, transparent, caducous, dense on young leaves and shoots with a rather lanate, greyish appearance and on all parts of the inflorescence except inner surface of bracts and tepals, less dense to nearly absent on old stems, leaves and old fruit capsules
Morphology Leaves
Leaves alternate, blade 2.4 - 9.0(- 10.2) x 1.9 - 7.6(- 8.9) cm, narrowly to broadly ovate, rarely very broadly ovate or orbicular, thinly chartaceous; drying brownish above, greyish-green below, sometimes almost black, usually with black glandular spots on lower surface near point of petiole insertion; margins entire, base cordate to hippocrepiform, sinus (3 -)5 - 19 mm deep; apex (5.8 -)7.5 - 15.8(- 20) mm long, acuminate to caudate (in younger leaves) with a 2.3 - 3.3(- 5.4) mm long, deltoid, dark brown to black forerunner tip, veins 3 - 5, with a smaller, often bifid, vein to each basal lobe, primary venation prominent on leaf blade lower surfaces; petiole (0.7 -) 1.0 - 5.5 cm long, dark brown to black, terete but channelled on upper surface, lateral nodal spines ("stipules" of Burkill 1960), recurved, to 2.2 mm long, fleshy and sometimes hard to see when dry, colour as stem/ petiole
Morphology Reproductive morphology Flowers
Male flowers, scent not recorded, pedicellate, pedicel of the first fertile flower 0.6 - 1.3 mm long, slender, sometimes slightly broader towards the torus, flowers in bud short- pedicellate to subsessile, tepal whorls weakly differentiated, tepals 6, rotate, free or partly fused at the base (difficult to distinguish between fused tepal bases and torus), free parts of tepals 0.6- 1.3 x 0.4- 0.9 mm, inserted on the rim of a saucer-shaped, (0.2 -)0.3- 0.6 x 0.6 - 1.3 mm torus which is darker brown than the tepals when dry; tepals broadly elliptic to rotund, apex short-acuminate to obtuse, membranous in texture; stamens 6, inserted at the centre of the torus, erect to spreading, apices divergent, filaments 0.15 - 0.35 mm long, anthers 0.15 - 0.25 x 0.1 - 0.2 mm, oblong to elliptic, dorsifixed, making a T-shape with the filament, held in the mouth of torus; pistillode 3 small fleshy projections at the centre of the torus Female flowers scent not recorded, subsessile, ovary c. 1.7 - 3.1 mm long, 3-angled, oblong-elliptic, tepals more clearly differentiated into 2 whorls than in male flowers, 6, outer whorl 1 - 1.5 x 0.45 - 0.75 mm, narrowly ovate to ovate, apex short acuminate to obtuse, membranous; inner whorl 0.5 - 1.2 x 0.5 - 0.8 mm, orbicular to ovate, apex obtuse to rounded, membranous; all whorls inserted on dark brown torus 0.5 - 1 mm in diameter, shallower than male; staminodia 6, in 2 whorls, erect to spreading tiny projections, styles 3, fused to form an erect 3-lobed column 0.15 - 0.3 mm long, stigmas on slender arms (free part of style) 0.1 - 0.25 mm long, spreading, bifid stigma lobe 0.1 - 0.2 mm long
Morphology Reproductive morphology Fruits
Capsule 16 - 26 x 8 - 16 mm, ascending at c. 45 - 300 to axis at dehiscence, oblong to oblong-elliptic or oblong to obovate in outline, base shallowly cordate to rounded, apex rounded, tepals persistent at capsule apex but much reduced in size, opening from apex to expose seed, wing basal and therefore concealed
Morphology Reproductive morphology Inflorescences
Female inflorescences 1 per axil, to 24 cm long, simple, spicate, drying light brown to dark rusty brown, pendent, subterete, winged, a single flower at each node; floral bract 2.8 - 4.9 x 0.9 - 1.3 mm, otherwise as male cymule bracts, bracteole (1.5 -)1.8-2.4 x 0.5-0.8 mm, like floral bract but smaller Male inflorescences 1 - 4 per axil, usually simple but sometimes compound with up to 5 partial inflorescences through suppression of leaf formation on axillary shoots, partial inflorescences pendent, racemose, with a cymule at each node comprising a basal sterile flower and 2 - 5 fertile flowers, one or two flowers per cymule open at any one time, cymules 1 - 7 mm apart, drying dark to light brown depending on hair density; primary axis (4.3 -)5- 30(-35) cm long with a 0.25- 1.6 cm long sterile basal region (peduncle), subterete with longitudinal furrowing, winged; cymule bract (2.0 -) 2.6 - 4.6(- 5.5) x 0.7 - 1.4(- 1.6) mm, narrowly lanceolate to narrowly ovate, sometimes asymmetric with one side wider than the other, base clasping the point of insertion of the cymule on the rachis (cymule subsessile), keeled, apex long-acuminate, membranous to thinly membranous towards the apex, midrib thickened; first floral bract (1.2 -) 1.5 - 2.1(-3.1) x 0.5- 1.2 mm, lanceolate to narrowly ovate, thinner than the cymule bracts, subsequent floral bracts smaller
Morphology Reproductive morphology Seeds
Seed winged at base only, 4.5 - 6.3 x 3.1 - 4 mm (immature) excluding wing, probably oblong when mature, apex rounded to truncate, flattened- reniform when mature, dark chestnut brown; wings too immature to measure, translucent, pale to dark golden-brown.
Morphology Stem
Stems left-twining, to 4.5 mm in diameter, subterete with longitudinal furrowing, unarmed, green with purple stripes or blotches when fresh, drying a dark rusty brown to purplish-black, sometimes with two toothed wings towards the base of the stem on young individuals
Note
Male plants of Dioscorea sterilis can most readily be distinguished from D. trichantha in the field through the conspicuous cymule bracts and different altitudinal range: at altitudes below 900 m, D. sterilis is encountered, while above 1000 m, it is D. trichantha. The determination can then be confirmed through the presence of a sterile basal flower in each cymule and the shape and depth of the torus in fertile flowers. Female plants are best separated from those of D. trichantha using the differences in indumentum and their collecting altitude. One of Perrier's specimens proved problematic during our research. This was Perrier 12369. The label states that its collecting locality was "Centre, Ouest Betsileo, entre Ivato et la Mania". There are seven sheets of this collection at P and three at K. Of the three K sheets, one is sterile, and is probably Dioscorea trichantha based on its indumentum. The second has female flowers and fruits, plus a scrap of flowering male material. This is D. sterilis. The third sheet, which arrived at Kew much later and does not bear Perrier's handwriting, has small pieces of male flowering material of both taxa. Thus it appears that more than one specimen was combined in error after collection under a single collecting number. The morphological similarity between the two species, especially their vegetative organs, makes this a possibility, and it might explain the large number of herbarium sheets involved. The locality on the label can only apply to D. trichantha because it is at c. 1400 m altitude. The K specimen has been separated into 12369A (D. sterilis) and 12369B (D. trichantha).
Type
Madagascar, Mahajanga Prefecture, au dessus de l'Ambodiria, 1 km a l'E d'Ambinda (RN 9, pres de Antsalova), 18°38'S, 44°42'E fl. 3 Dec. 1992, Labat & Deroin 2270 (holotypus P, isotypi K, TAN).
Vegetative Multiplication Bulbils
Bulbils not present
Vegetative Multiplication Tubers
Tubers to at least 60 cm long, orientated vertically, one growing and one shrinking, cylindric, tapering to apex, epidermis dull brown
Vernacular
Bako (unknown language, Seyrig 367), Ovy or Oviala (Sakalava). These names are also applied to other Dioscorea species.

[KBu]
Use
The tubers are edible when cooked and are said (by Seyrig) to have an excellent flavour.

Native to:

Madagascar

Dioscorea sterilis O.Weber & Wilkin appears in other Kew resources:

Date Reference Identified As Barcode Type Status
Jan 1, 2004 Labat, J.-N. [2270], Madagascar K000400304 isotype
Labat, J.N. [2271], Madagascar K001148378
Perrier de la Bâthie, J.M.H.A. [17398], Madagascar K001148384
Nusbaumer, L. [LN3068], Madagascar K000062179
Wilkin, P. [1150], Madagascar K001148387
Wilkin, P. [1151], Madagascar K001148389
Wilkin, P. [1151], Madagascar K001148391
Perrier de la Bâthie, J.M.H.A. [12369], Madagascar K001148385
Wilkin, P. [1150], Madagascar K001148388
Hanitrarivo, R.M. [HRM173], Madagascar K000062178
Hanitrarivo, R.M. [RFB087], Madagascar K000062177
Wilkin, P. [1151], Madagascar K001148390
Labat, J.N. [2271], Madagascar K001148379
Perrier de la Bâthie, J.M.H.A. [12369], Madagascar K001148386
Perrier de la Bâthie, J.M.H.A. [17398], Madagascar K001148382
Perrier de la Bâthie, J.M.H.A. [17398], Madagascar K001148383
Perrier de la Bâthie, J.M.H.A. [12369], Madagascar K001148380
Baron, R. [6825], Madagascar K001148381

First published in Kew Bull. 60: 286 (2005)

Accepted by

  • Govaerts, R., Wilkin, P. & Saunders, R.M.K. (2007). World Checklist of Dioscoreales. Yams and their allies: 1-65. The Board of Trustees of the Royal Botanic Gardens, Kew.

Literature

Kew Bulletin

  • --- & Perrier de la Bathie, H. (1950). Dioscoréacées. In: H. Humbert (Ed.), Flore de Madagascar et des Comores. Paris.
  • Baker, J. G. (1883). Contributions to the Flora of Madagascar Part III. Incompletae, Monocotyledons and Filices. J. Linn. Soc., Bot. 20: 237 - 304.
  • Burkill, I. H. (1960). The organography and the evolution of the Dioscoreaceae, the family of the yams. J. Linn. Soc., Bot. 56: 319 - 412.
  • IUCN. (2001). IUCN Red List Categories: Version 3.1. Prepared by the IUCN Species Survivial Commission, Gland, Switzerland & Cambridge, U.K.
  • SPSS (2002). SPSS version 11.5 for Windows. SPSS Inc.
  • Sokal, R. R. & Rohlf, F. J. (1995). Biometry: the principles and practice of statistics in biological research. 3rd edition. W. H. Freeman, New York.
  • Wilkin, P. (1999). A morphometric study of Dioscorea quartiniana A. Rich. (Dioscoreaceae). Kew Bull. 54: 1 -18.
  • Wilkin, P., Andrianantenaina, W. P., Jeannoda, V., & Hladik, A. (2008). The species of Dioscorea L.(Dioscoreaceae) from Madagascar with campanulate tori, including a new species from Eastern Madagascar.  Kew Bulletin63(4), 583-600.

Herbarium Catalogue Specimens
Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

Kew Backbone Distributions
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0

Kew Bulletin
Kew Bulletin
http://creativecommons.org/licenses/by-nc-sa/3.0

Kew Names and Taxonomic Backbone
The International Plant Names Index and World Checklist of Selected Plant Families 2021. Published on the Internet at http://www.ipni.org and http://apps.kew.org/wcsp/
© Copyright 2017 International Plant Names Index and World Checklist of Selected Plant Families. http://creativecommons.org/licenses/by/3.0