PN-6373 



Figure?. — Tubers of D. transversa. 



to obtain named cultivars from experiment stations and research work- 

 ers. Named cultivars in old publications are not always available. Fur- 

 thermore, common names are not always reliable and differ from one 

 region to another. Any listing of cultivars should be interpreted with 

 caution. It is also important to know the cultivars because poisonous 

 varieties of D. dumetorum, D. hispida, and D. pentaphylla are often 

 planted to confound thieves. The use of these yam species without 

 foreknowledge or precaution is dangerous. 



The most extensive listing of cultivars of D. pentaphylla and D. 

 yiurnniularia has been given by Bourret (i), who lists more than 20 

 named varieties of the former and more than 30 of the latter. Even when 

 based on collections from areas other than the French islands of the 

 Pacific, the number of varieties is impressive. 



In Cameroon, a study of D. dumetorum cultivars (10) identified 16 



15 



