The genus Vigna is a large pantropical genus with 82 described species distributed among 7 subgenera, namely Ceratotropis, Haydonia, Lasiospron, Macrorhyncha, Plectotropis, Sigmoidotropis and Vigna, and 150 species (Maréchal, Mascherpa, & Stainer, 1978; Tomooka, Vaughan, & Moss, 2002).