693 



///.—Thornier, Blutenpfl. Afr. t. 21; Burkill, Gardens' BulL 

 Straits Sett, Nov. Uth, 1918, t. 8. (roots). 



Vernac. names. — Kosain rogo, rogon biri (Haiisa, Dalziel) ; 

 Idiya (Chindao, Gazaland, Swynnerton); [Obabit Iwa, Ndisimo 

 Iwa, Afia Edidia, Eba Edi (Old Calabar) Burkill, Johnson']. 

 Nfamka or Nfaml^o (Gold Coast, Burlill) ; Esura (Lagos, Burhill, 

 MacGregor, Daivodu), Ona (Aguku, S. Nigeria, Thomas), 



Lagos, Old Calabar, Ziingeru, Nupe and Yola, in Nigeria, 

 also known from Uganda, NyasaJand, Gold Coast and Gazaland. 



A poisonous yam, root as large as a man's fist, Aburi (Johnson^ 

 No. 482, Herb. Kew), frequently found growing wild with edible- 

 tubers, said to develoj:? well with little care. Old Calabar (Johnson, 

 Herb. Kew); '' Nfamko '' is stated to be edible, but medicinal 

 on the Gold Coast; " Esura " has been eaten in Singai)ore Avithoufc 

 causing any discomfort, but it is shghtly bitter (Burkill, I.e. p. 91) ; 

 plant used {vrith. others) in the preparation of Arrow poison , 

 Manganja Hills, Nyasaland (Meller, Herb. Kew) ; spherical 

 tubers eaten by the Natives only in time of famine and then 

 only after special pounding and washing to expel poisonous 

 juice, sometimes the cause of death (Swynnerton, Herb. Kew); 

 '' but with cultivated yams in West Africa, whose exact value 

 has not yet been made clear," and " as D. hirsida is a most 

 important famine food of India and Malaya, so does D, dumetorum 

 appear to be a famine food in Africa : but it appears to be more, 

 for whereas D, hirs^ita has given no cultivated races D. dnme- 

 torum has, and the conflicting statements of travellers as to its 

 utihty are to be explained in the light of this " (Burkill, Lc. 

 p. 1)1). 



When D. dumetorum sprouts, it throws up a stout prickly 

 shoot, with alternate leaves and these leaves have the pecuharity 

 that the base of the petiole is bent downwards to aid the plant 

 in chmbing (I.e.). In Gazaland it is reported to make very rapid 

 growth after the annual jungle fires and grows straight upward 

 till top-heavy, then falls and climbs over any vegetation on which 

 it happens to rest (Swynnerton, Journ. Linn. Soc. xl. 1911, p. 212; 

 D. quartiniana) . 



Dioscorea rotundata, Poir. in Lamarck, EncycL SuppL ilL 



(1813) p. 139. 



Tubers large, yellow-fleshed, with a thick neck and somewhat 

 uneven surface : whole plant glabrous ; stems cUmbing, young 

 and old shoots prickly (Burkill); " strongly prickly to near the 

 top of the vine " (Johnson) ; leaves cordate-orbicular, shortly acu- 

 minate, about 4 in. in diameter, 7 -nerved, papery, dark green 

 above, paler below; petiole slender, about 3 in. long " sometimes 

 prickly" (Johnson). Male spikes 1-4 in the axil of each leaf; 

 about 2| in. long, about -iO-flowered (Burkill). 



7/Z.— Burkill, Gardens, Bull. Straits Setth Nov. 11th, 1918, 

 p. 90 (leaves), t. 7 (roots). 



Vernac. names. — [Alo Iganyan or Iganyan Alu (S. Nigeria) ; 

 Akpana, Efiam (Old Calabar) BurkUl, Johnson.] Affon or Affoo 



