THIS important study is by one of the authors of the revision of the Eastern Dioscoreas. It will prove invaluable in compiling any general account of the genus ia Africa. Twenty-three species are recorded with several varieties for some of them; two of the species are here described for the first time. These species of the Congo are attributed to six sections of which four twist to the left. A definition of each section is given, and a key to the species is provided for each plurispecific section. A full history and synonymy of every species will be found, together with a comprehensive statement of the known collectors and its distribution within and without the Belgian Congo. Many interesting notes are furnished on the depth below ground-level at which the tubers are seated, on their edibility and method of preparation for food; poisonous properties; bulbil production and self-protective measures. Of peculiar interest and value are the discussions on the origin, evolution and “ennoblement” (improvement and refinement by selective cultivation) of the most-prized yams. It is indicated that some of the problems involved can only be solved in the field and that “the paper is intended to direct all who are able to study the Congo Dioscoreas alive to points worthy of their particular attention”.
Notes on the Genus Dioscorea in the Belgian Congo
By I. H. Burkill. (Extrait du Bulletin du Jardin botanique de l'Etat, Vol. 15.) Pp. 48. (Bruxelles: Jardin botanique de l'Etat, 1939.)