Rhizothera Gray, List Gen. Birds, 2nd ed., p. 79 (1841).
Type, Perdix longirostris Temm.
The genus Rhizothera contains a single species of Partridge at once distinguished from all others by its long, heavy and much bent down bill. The tail has twelve feathers ; the wing is short and rounded, the first primary about equal to the tenth and the fifth and sixth subequal and longest; the tarsi are stout and long and are furnished with short blunt spurs in both sexes; the claws are straight and small and there is a small hind claw. The sexes differ from one another in coloration.