Japan Flora: Short-pubescent annual or biennial 30-60 cm. high, with a branched procumbent base; stipules semiovate, somewhat toothed, the leaflets broadly obovate, 7-17 mm. long, 6-15 mm. wide, denticulate on the upper half; heads ovoid, on peduncles longer than the petioles, the bracteoles minute and subulate, the pedicels very short; calyx 1.5 mm. long; legumes semicircular, smooth, nerved, black when mature.