Calyx. Perianthium monophyllum, ovato-oblongum, parum inflatum, villosum; ore quinquedentato, inæquali; persistens.
Corolla papilionacea:
Vexillium longius, lateribus reflexis, ungue longitudine calycis.
Alæ duæ, oblongæ, vexillo breviores.
Carina compressa, longitudine alarum, alis similis.
Stamina. Filamenta decem, connata, assurgentia. Antheræ simplices.
Pistillum. Germen oblongum. Stylus simplex, adscendens. Stigma obtusum.
Pericarpium. Legumen subrotundum, tectum intra calycem, minimum, bivalve.
Semen unum, alterumve.
Empalement. Cup of one leaf, oblong egg-shaped, a little swelled, and hairy; mouth cut into five unequal teeth; permanent.