PN-5860 



Figure 2. — Leaves of D. trifida showing variable amounts of lobing, petiole 

 wings, and mosaic virus. 



been recognized in Trinidad and in Guadaloupe. The best study of 

 the species is that of Henry (18) , sl Ph. D. thesis from McGill 

 University. The most extensive breeding work has been done by 

 the Institut National de la Recherche Agronomique (INRA) plant 

 breeding station (10, 11). 



BOTANY 



Classification 



Dioscorea trifida belongs to the small section Macrogynodium, 

 a South and Central American section. The species is easily dis- 

 tinguished from related species such as D. bernoulliana, D, uro- 

 phylla, and D. dugesii by the prominent wings of the stem (3)- 

 A list of synonyms would be long and will not be given here, but 

 those names most likely to be encountered are D. brasiliensis Willd. 

 and D, brasiliana Poir. Synonyms for its scientific name, D. 

 triphyla and D. triloba, often found in old botanical literature, 

 probably refer at times to D. trifida. Among common names are 

 yampi (yampie) in northern South America and Jamaica, aja or 

 aje in Cuba, maona in eastern Peru, mapuey in Puerto Rico, and 

 cushcush in many different regions. In Brazil, it is called "cara 

 doce" (sweet yam) (5). The French name is cousee-couche. 



4 



