Contains 7 accepted taxa overall.
Characteristics
Classification
Citation
DIOSCOREA Linnaeus, Sp. Pl. 1032. 1753, nom. cons. propos.
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TYPE: Dioscorea sativa Linnaeus, typ. cons. propos. Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 1: 535. 1913.
Species
| Scientific Name | Common Name | Herbarium Specimens | Status | Photos |
|---|---|---|---|---|
| Dioscorea alata | WHITE YAM | Not Native Y | ||
| Dioscorea bulbifera | AIR-POTATO | Not Native Y | ||
| Dioscorea dodecaneura | ORNAMENTAL YAM | Not Native | ||
| Dioscorea floridana | FLORIDA YAM | Native FAC (NWPL) | ||
| Dioscorea polystachya | CHINESE YAM; CINNAMON VINE | Not Native | ||
| Dioscorea sansibarensis | ZANZIBAR YAM | Not Native | ||
| Dioscorea villosa | WILD YAM; FOURLEAF YAM | Native FACW (NWPL) |
Identification Key
1. Leaf blade upper surface variegated whitish along the midrib, the lower surface pale green to purplish
1. Leaf blade upper surface not variegated, the lower surface green or glaucous
2
2. Plants rhizomatous; bulbils never produced in leaf axils; leaf margins entire or repand; petiole base never clasping; inflorescences regularly produced
3
2. Plants tuberous; bulbils produced in leaf axils; leaf margins lobed or entire; petiole base sometimes clasping; inflorescences absent or infrequent, or often only one sex present
4
3. Rhizomes yellow, nodes articulate, each bearing 1 dark, contrasting, somewhat deltate scale leaf or the dark vertical scar remaining once leaf falls; staminate inflorescences (1)2–5 in leaf axils; perianth of both staminate and pistillate flowers yellow to orangish yellow; stamens inwardly curved; thecae connate
3. Rhizomes brownish, nodes not articulate; staminate inflorescences solitary in leaf axils; perianth of both staminate and pistillate flowers greenish white; stamens erect; thecae distinct, widely spreading
4. Leaf blade unlobed
5
4. Leaf blades lobed, with a sinus, sometimes obscure
6
5. Stems broadly winged, 4-angular; leaves often opposite or subopposite, the blade base margin somewhat straight and sagittate and angled; seeds winged all around
5. Stems terete, usually unwinged; leaves alternate throughout, the blade base mostly evenly rounded; seeds unilaterally winged
6. Leaf blade hastate-cordate, margins 3-lobed, lobes rounded, blade apex acute or mucronate; petiole base not clasping
6. Leaf blade reniform, margins irregularly 3-5-lobed, lobes often elongate or acuminate, blade apex conspicuously caudate
Genus Synonyms
| Synonym | Full Citation | Basionym | Type |
|---|---|---|---|
| Borderea | Borderea Miégeville, Bull. Soc. Bot. France 13: 374. 1866. | TYPE: Borderea pyrenaica Miégeville | |
| Botryosicyos | Botryosicyos Hochstetter, Flora 27(1, Bes. Beil.): 3. 1844. | TYPE: Botryosicyos pentaphyllus Hochstetter | |
| Elephantodon | Elephantodon Salisbury, Gen. Pl. 12. 1866. | TYPE: Dioscorea eburnea Loureiro | |
| Epipetrum | Epipetrum Philippi, Linnaea 33: 253. 1864. | TYPE: Epipetrum humile (Bertero & Colla) Philippi (Dioscorea humilis Bertero & Colla) | |
| Hamatris | Hamatris Salisbury, Gen. Pl. 11. 1866. | TYPE: Dioscorea triphylla Linnaeus | |
| Helmia | Helmia Kunth, Enum. Pl. 5: 414. 1850; Abh. Koenigl. Akad. Wiss. Berlin 1848: 55. 1850. | TYPE: Helmia dregeana Kunth Lectotypified by Caddick et al., Taxon 51: 108. 2002. | |
| Higinbothamia | Higinbothamia Uline, Publ. Field Columb. Mus., Bot. Ser. 1: 414, t. 22. 1899. | TYPE: Higinbothamia synandra Uline | |
| Merione | Merione Salisbury, Gen. Pl. 12. 1866. | TYPE: Dioscorea villosa Linnaeus | |
| Nanarepenta | Nanarepenta Matuda, Anales Inst. Biol. Univ. Mexico 32: 143. 1962. | TYPE: Nanarepenta tolucana Matuda | |
| Oncus | Oncus Loureiro, Fl. Cochinch. 190, 194. 1790. | TYPE: Oncus esculentus Loureiro | |
| Peripetasma | Peripetasma Ridley, J. Bot. 58: 147. 1920. | TYPE: Peripetasma polyanthum Ridley | |
| Polynome | Polynome Salisbury, Gen. Pl. 12. 1866. | TYPE: Dioscorea alata Linnaeus Lectotypified by Caddick et al., Taxon 51: 108. 2002. | |
| Rajania | Rajania Linnaeus, Sp. Pl. 1032. 1753. | TYPE: Rajania hastata Linnaeus Lectotypified by Britton & Millspaugh, Bahama Fl. 80. 1920. | |
| Rhizemys | Rhizemys Rafinesque, Fl. Tellur. 4: 26. 1838 ("1836"). | TYPE: = Testudinaria Salisbury ex Burchell 1824. | |
| Sismondaea | Sismondaea Delponte, Mem. Reale Accad. Sci. Torino, ser. 2. 14: 394. 1854. | TYPE: Sismondaea dioscoreoides Delponte | |
| Strophis | Strophis Salisbury, Gen. Pl. 12. 1866. | TYPE: Dioscorea cirrhosa Loureiro | |
| Tamus | Tamus Linnaeus, Sp. Pl. 1028. 1753. | TYPE: Tamus communis Linnaeus Lectotypified by M. L. Green, Prop. Brit. Bot. 191. 1929. | |
| Testudinaria | Testudinaria Salisbury ex Burchell, Trav. S. Africa 2: 147. 1824. | TYPE: Testudinaria elephatipes (L'Heritier de Brutelle) A. Dickson (Dioscorea elephantipes L'Heritier de Brutelle) Lectotypified by E. Phillips, Gen. S. African Pl., ed. 2. 208. 1951. | |
| Ubium | Ubium Cothenius, Disp. 25. 1790. | TYPE: Ubium quadrifarium J. F. Gmelin |