Neonotonia wightii, the perennial soybean, is a species of flowering plant in the family Fabaceae, native to subSaharan Africa, Yemen, India, and Sri Lanka, and widely introduced as a forage in Brazil, Bolivia, Paraguay, northern Argentina, the Mascarene Islands, Peninsular Malaysia, Java, New Guinea, Queensland and New South Wales in Australia, and Fiji. It is shade tolerant.
The following subtaxa are accepted: