Japan Flora: Pubescent annual 10-20 cm. high, with firm, prostrate stems; stipules semiovate, entire or slightly toothed; leaflets obovate-cuneate, 7-10 mm. long, rounded at apex, denticulate on upper half; heads 2- to 5-flowered; calyx 2-2.5 mm. long; legumes 4- to 5-times spirally coiled, about 4 mm. across, spiny on the nerves and on margins.
Naturalized in our area. Europe, Near East, and n. Africa.