African yam beans originated in sub-Saharan Africa and are cultivated as a food and nutritional security crop, making them the most economically important Sphenostylis sp. They have protein-rich seeds that contain “over 32% essential amino acids” as well as tuberous roots with a 19% protein content. The tubers are similar to sweet potatoes and are often prepared in similar ways. The tubrers come in a variety of shapes that are ready to harvest in 5-8 months. 

 

Reference: Abberton, Michael; Taofeek Adegobeyga, Benjamin Faloye, Rajneesh Paliwali, and Olaniyi Oyatomi. African yam bean, Sphenostylis stenocarpa, 

International Institute of Tropical Agriculture (IITA), P.M.B. 53220, Ibadan, Oyo State, Nigeria.