Dioscorea.'] cxxxix, DioscoREACEiE (baker). 415 



Stem terete. 



Leaves and flowers glabrous. 



Leaves cordate orbicular . . . . . . 11. J), zanzibarensis. 



Leaves ovate, shallowly cordate . . . . 12. Z). prehensilis. 



Leaves ovate, deeply cordate . . . . 13. D. abyssinica. 



Leaves and flowers hairy 14. 2). schimperiana. 



Leaves compound. 

 Leaves trifoliolate. 

 Leaflets subsessile. 



End leaflet obovate 15. 2). dumetorum. 



End leaflet oblong 16. D. phaseoloides. 



Leaflets distinctly stalked ]7. D. Vespertilio. 



Leaves 5- rarely 7- foliolate. 

 Male spikes dense. 



Leaflets obovate or oblong . . . . 18. Z). beccariana. 

 Leaflets lanceolate or oblanceolate . . .19. B. Stuhlmanni. 

 Male spikes lax 20. Z>. ITolstii. 



1. D. (Helmia) sativa, Linn. Sp. Plant, edit. i. 1033 {excl. sijn.). 

 Glabrous in all its parts. Rootstock large, tuberous, edible. Leaves 

 distinctly petiolate, simple, ovate or orbicular, cuspidate, deeply cordate, 

 sometimes 1 ft. long and broad, membranous, 7-9-nerved from the 

 apex of the petiole, often bearing bulbils in their axils. Male flowers 

 in lax slender fascicled spikes, often produced from leafless nodes ; 

 bracts minute, ovate. Perianth -^^-^ in. long, oblong in bud ; segments 

 linear. Fertile stamens 6. Female flowers in very lax spikes. Capsule 

 oblong, J-1 in. long. Seeds broadly winged at the base only. — Hort. 

 Cliff, t. 28; Schum. Beskr. Guin. Plant. 447; Benth. Fl. Austral, vi. 

 461 ; Hook. f. Fl. Brit. Ind. vi. 295. D. latifolia, Benth. in Hook. 

 Niger Fl. 535 ; D. bulbifera, Harms in Engl. Pfl. Ost-Afr. C. 146. 



Commonly cultivated throughout Tropical Africa. 



Upper Guinea. Sierra Leone : Kinsuta, Scott-Elliot, 423o ! and without pre- 

 cise locality, Don ! Niger Territory : Nupe ; Jeba, Barter ! at the confluence of the 

 Niger and Benue Rivers, Barter ! Niger Delta : Nun River, Vogel, 30 ! Fernando 

 Po, Milne ! Cameroons : Yaunde, Zenker Sf Staudt, 412 ! 



irile ]Land. Galabat : Matamma, Schweinfurth^ 593 ! British East Africa : 

 Unyoro, SpeTce Sf Grant ! 



Xio-wer Guinea. Isle of St. Thomas, Moller, 4 ! Gaboon : Munda ; Sibange 

 Farm, Soyaux, 77 ! 211 ! Angola : Golungo Alto, Welwitsch, 4037 ! 



IMCozaml). Dist. German East Africa : Usambara ; Duga, Hoist, 3160 ! 

 Portuguese East Africa : Lupata, on the River Zambesi, Kirk ! Shamo, near the 

 mouth of the River Shire, Kirk ! British Central Africa : Boruma, on the River 

 Zambesi, Menyharth ! Nyasaland ; Shire Highlands, JBuchanan, 259 ! and without 

 precise locality, Buchanan, 11 ! 1185 ! 



2. D. Buchananiy Benth. in Hook. Ic. t. 1397-8. Stems twining, 

 glabrous, unarmed. Leaves all alternate, distinctly petiolate, cordate- 

 ovate, cuspidate, sometimes as broad as long and palmately lobed, 

 reaching J ft. long, moderately firm, glabrous on botli surfjices, 5-7- 

 nerved from the apex of the petiole. Male flowers in dense short 

 usually solitary axillary racemes ; bracts lanceolate, shorter than the 

 pedicels. Male perianth glabrous, very large for the genus, J in. long, 



