Japan Flora: Stoloniferous peren­nial; stems mostly erect, 10-80 cm. long, usually branched, of­ten slightly scabrous, white-pilose at the nodes; leaves narrowly rhombic-ovate to broadly lanceolate, 2-4 cm. long, 1-2 cm. wide, subobtuse, narrowed to a winged pedolelike base, coarsely obtuse-toothed; flowers in loose verticils; calyx about 3 mm. long, 5-toothed, the teeth narrowly deltoid, spine-tipped; corolla white, about 3 mm. long; nutlets 1.5 mm. long, broadly cuneate at base, truncate and very slightly undulate at apex. Aug.-Nov. Wet places.

Hokkaido, Honshu, Shikoku, Kyushu. Korea, Manchuria, and China.

var. ramosissimus. L.  Stems low, 10-30 cm. long, much-branched; leaves smaller. Honshu, Shikoku, Kyushu. Korea.