Oxytropis DC.
(Barneby, 1952; Welsh, 2001)
Three hundred to 400 species, North
America, Europe, Asia.
Oxytropis is very similar to Astragalus, but differs in having
corollas with a strongly beaked keel and different base chromosome number. The
chromosome number of Oxytropis is
closer to that of some Old World species of Astragalus,
suggesting that it is an independent lineage in the New World. Preliminary
molecular evidence indicates Oxytropis
is not nested within Astragalus
(Wojciechowski et al., 1999).