Species of the genus Dioscorea (Yams) in tropical and subtropical Africa

Abstract

A study was conducted on species of the genus Dioscorea in tropical and subtropical Africa. This review covered aspects of botany, dissemination and ecology, as well as ethno-botanical, nutritional, phytochemical, pharmacotherapeutic, and toxicological data concerning yams in these African regions. Yams (Dioscorea) are among the most prevalent plant species in tropical areas, requiring high temperatures (between 25 and 30 °C) and substantial rainfall (between 1000 and 1800 mm) for optimal growth and yield. Nearly 27 species from this genus have been recorded in these regions, despite their complex morphological characteristics and numerous varieties. They are primarily utilized for food, but serve also various socio-traditional and pharmacotherapeutic needs within African communities. Nutritional data indicate that Dioscoreaceae possess significant nutritional value, with satisfactory evaluations of water content, macronutrients (carbohydrates, lipids, proteins), and micronutrients (vitamins and minerals). Additionally, they are an important source of bioactive phytochemical compounds, including polyphenols, steroids, saponins, allantoin, and particularly polysaccharides and diosgenin, which endow them with remarkable anti-radical and pharmacotherapeutic properties. However, some species are toxic and require prior detoxification before consumption, either through soaking, cooking, or a combination of both.

Keywords: Dioscorea, Traditional food, Tubers, Food security, Tropical and subtropical Africa