692 



Leone, Ivory Coast, Togoland, Dahomey, Gaboon, Angola and- 

 probably throughout Tropical Africa and the West Indies, 



Grown largely in former days as a food for Negro slaves- 

 (Kew Bull. 1919, p. 364); cultivated in Nupe (Barter, I.e.), the 

 common cultivated yam in Munshi (Dalziel, I.e.). Of all the 

 species of Dioscorea cultivated in Africa, D, cayenensis, Lamk- 

 is certainly the one which takes first place; there are many 

 varieties — of which fifteen have been verified on the Ivory Coast 

 and a score in Dahomey (Chevalier, Bull. Soc. Bot. France, I.e. 

 p. 225). In Unyoro the roots of " Kama " are eaten in times o£ 

 great scarcity (Dawe, Herb. KeAv). 



On a specimen of roots received from West Tropical Africa 

 (grown at Kew) in the Herbarium, it is stated that " this species- 

 has a large cluster of fleshy tubers like those of a DaJilia, which. 

 l)roduce from various parts of their surface slender wiry roots 

 armed with spines and at the base of tlie stem and top of the 

 cluster of tubers a crowed of thick and very tough roots armed 

 with strong spines form a dense matted thorny mass 2 ft. or 

 more in diameter, arching over and completely covering the 

 tubers, thus serving to protect them from being grubbed ujj by 

 animals." This specimen was the subject of a paper by Dr. Scott 

 in the Annals of Botany (seq,); it flowered at Kew in 8eptember 

 1894. 



On the Cross River Expedition in 1899, the writer noted large- 

 stores of yams that w^ere very probably D. cayenensis — this was. 

 especially so between Old Calabar and Uw^et, at a village called 

 Unan, where they were arranged in bin-Hke structures made of 

 strong poles — one such being 120 ft. by 15 ft., carrying approxi- 

 mately 10,500 3^ams and ten more structures of about the same* 

 dimensions were in course of preparation. 



Recently a large collection of herbarium specimens and tubers 

 have been received at Kew from the Directors of Agriculture^ 

 Nigeria and Gold Coast, for determination in the course of the 

 preparation of the monograph on the genus referred to {seq.). 

 The results will be published in due course ; but meantime tliey 

 have so far been identified as being chiefly referable to thi.s 

 species and a few to chimetornm and rotundata {qA\). 



ReJ. — '' On two New Instances of Spinous Roots," Scott, in 



Annals of Botany : (1) Dioscorea prehensilis, Benth. xi. 1897^ 



pj). 327-330. " The Root-Structure of Dioscorea preJiensiliSy"^ 



Hill & Freeman, I.e. xvii. 1903, pp. 413-423. " Sur les 



Dioscorea cultives en Afrique Tropicale et sur un cas de selection 



naturelle relatif a une espece spontanee dans la foret vierge,'" 



Chevalier, in Compt. Rendus, Acad. Sc. Paris, cxHx. 11th Oct. 



1909, pp. 610-612. ''Dioscorea cayevensis, Lamk. {D. pre- 



hensilis, Hook.), Chevalier, in Bull. Soc. Bot. France, hx. 1912 



pp. 223-227.—" The White or Eight Months Guinea Yam/'' 



BurldlL in the Gardens Bull. Str. Sett, ii. Nov. 11th, 1918^ 

 pp. 87-89. 



Dioscorea dumetorum, Pax\ FI. Trop. Ah. VII. p. 419. 



