Rafael Govaerts & Richard M K Saunders 
World Checklist of Dioscoreales [PDF ebook] 

Dioscoreales are a small but systematically and economically significant order of monocotyledons. The most diverse and important member is the yam genus, Dioscorea L., a source of dietary starch at macroeconomic to rural community levels. Other species of Dioscorea provided the chemical basis of corticosteroid drugs and oral contraceptives. Ally families comprise the unusual, largely achlorophyllous (heteromycotrophic) Burmanniaceae and the relatively unspecialised Nartheciaceae.The World Checklist of Dioscoreales lists all validly published names of yams and their allies, providing the source of their publication and indication of which names are currently accepted and which are synonyms, making it a standard nomenclatural reference for further research into this important family.