Japan Flora: Plant very delicate, glabrous except the calyx-lobes; stems much branched, appressed to the ground, many-leaved; leaves spread­ing, broadly linear to broadly lanceolate, 3-5 mm. long, 1 (-2) mm. wide, obtuse, shorter than the internodes of branches, scmiclasping at base, entire, sessile; flowers solitary in axils, sessile; ealyx 2.5-3 mm. long, tubular-campanulate, 5-ribbed, 5-lobed, the lobes narrowly deltoid, acute, sparsely ciliate, slightly spreading at tip; corolla minute, pink; capsules oblong, nearly as long as the calyx-tube, enclosed in the calyx; seeds fusiform-ovoid, obtuse, yellow-brown, nearly smooth, about 0.3 mm. long. July-Oct. Paddy fields and wet riverbanks in lowlands.

Honshu, Shikoku, Kyushu. Korea, Ryukyus, Formosa, China, India, Malaysia, and Australia.