A revision of the genus Dysolobium (Papilionaceae) and the transfer of subgenus Dolichovigna to Vigna

Dysolobium is a small legume genus, consisting of 4 species. It is closely related to Vigna, from which it differs by the shape of the wing petals and by the velvety, almost woody pods. Recently the genus has been divided into 2 subgenera, but in this paper the subgenus Dolichovigna is transferred back to Vigna. Possible relations between Dysolobium and genera as Vigna, Phaseolus, Canavalia, Dolichos, Psophocarpus, and Pueraria are discussed. Vigna seems to be the most closely related genus. Dysolobium is a Southeast Asian genus, two species of which are endemic and two more widespread; one of the latter ranges from India to Java (not extending more eastwards). The plants prefer a climate with a seasonal drought. Vigna pilosa is the only species in Vigna subgenus Dolichovigna. Vigna clarkei is excluded from this subgenus.