Japan Flora: Glabrous annual; stems branched at base, 8-20 cm. long; leaves lanceolate or oblong-lanceolate, sometimes narrowly lanceolate, 1-3(-4) cm. long, 3-5(-8) mm. wide, acute or subobtusc, narrowed at base, obsoletely short-toothed, obsoletely penninerved; flowers solitary in upper axils，the pedicels spreading, nearly as long as the capsules; calyx 4-5 mm. long, the segments linear; corolla creamy white, about 1 cm. long; lower anther-locule of the fertile stamens short spine-tipped; capsules linear, 3 or 4 times as long as the calyx. Aug.-Oct. Wet places in lowlands.

Honshu, Shi­koku, Kyushu. Korea, China, India, and Malaysia.