Robinia (Leguminosae: Papilionoidea)

Robinia is a temperate North American genus of four species. A broadly defined Robinia hispida of the southeastern United States consists primarily of sterile, mostly triploid clones; fertile, diploid kinds are locally endemic in the southern Appalachians. Robinia viscosa, of restricted natural distribution in the southern Appalachians, includes both fertile and sterile types. The other two species are R. neomexicana of the southwestern United States and the widely distributed R. pseudoacacia. There is evidently some hybridization between species both in nature and in culture. One new combination is listed: Robinia neomexicana var. rusbyi (Wooton & Standley) Martin and Hutchins ex Peabody.