Genus: Dioscorea (yams)

Life > eukaryotes > Archaeoplastida > Chloroplastida > Charophyta > Streptophytina > Plantae (land plants) > Tracheophyta (vascular plants) > Euphyllophyta > Lignophyta (woody plants) > Spermatophyta (seed plants) > Angiospermae (flowering plants) > Monocotyledons > Order: Dioscoreales > Family: Dioscoreaceae

The number of species in this cosmopilitan genus is quoted as anything between 600 and about 860, of which 23 are native to southern Africa. The term yam in the USA often refers to a variety of sweet potato rather than to true yams. Tubers cooked as a vegetable (high in starch). Diosgenin, a precursor of progesterone and cortisone is produced commercially using a number of species.

Species native to southern Africa

List from Archer (2003), Wilkin et al. (2010), Flora of Zimbabwe and Flora of Mozambique.

Dioscorea asteriscus
Dioscorea brownii
Dioscorea buchananii Recorded from Zimbabwe and Mozambique.
Dioscorea bulbifera Recorded from Zimbabwe.
Dioscorea burchellii
Dioscorea cochleari-apiculata
Dioscorea cotinifolia
Dioscorea diversifolia
Dioscorea dregeana
Dioscorea elephantipes
Dioscorea dumetorum Recorded from Zimbabwe and Mozambique.
Dioscorea hemicrypta
Dioscorea hirtiflora
Dioscorea praehensilis Recorded from Zimbabwe and Mozambique.
Dioscorea quartiniana
Dioscorea retusa
Dioscorea rupicola
Dioscorea sansibarensis Recorded from Zimbabwe and Mozambique.
Dioscorea schimperiana Recorded from Zimbabwe and Mozambique.
Dioscorea stipulosa
Dioscorea strydomiana Endemic to Mpumalanga (Wilkin et al. 2010).
Dioscorea sylvatica
Dioscorea undatiloba

Publications

• Archer, R.H. 2003. Dioscoreaceae. In Germishuizen, G. & Meyer, N.L. (eds), Plants of southern Africa: an annotated checklist. Strelitzia 14: 1047-1049. National Botanical Institute, Pretoria. 

• Wilkin P., Burrows J., Burrows S., Muasya A.M. and van Wyk E. 2010. A critically endangered new species of yam (Dioscorea strydomiana Wilkin, Dioscoreaceae) from Mpumalanga, South Africa. Kew Bulletin 65: 421-433.