Japan Flora: Small perennial; roots elongate; stems 10-30 cm. long, slender, green, prostrate or decumbent from a short caudex, ascending above, tufted, with scattered minute curved hairs; leaves chartaceous, very short petiolate, elliptic to ovate or broadly lanceolate, 1-2.5(-3) cm. long, 3-12 mm. wide, acute to subobtuse at both ends, vivid green, slightly puberulous or glabrate, with a raised midrib beneath, the reticulated vein- lets rather prominent above; racemes loosely few-flowered, 1-3 cm. long, the peduncles short, supra-axillary; flowers purple; lateral sepals ovate, obtuse, rather petallike, 5-7 mm. long, accrescent after anthesis, to 10 mm. long, becoming green in fruit, the remaining sepals lanceolate, 3-4 mtn. long; petals connate, spreading above, 6-7 mm. long, the lowest one with a fimbriate appendage at apex; capsules flat, winged on the margins, rounded-cordate, retuse, 7-8 mm. wide, membranous, glabrous; seeds ellipsoidal, brown, about 2.5 mm. long, white- pilose, strophiolate on upper margin. Apr.-July. Grassy slopes in lowlands and hills.
Hokkaido, Honshu, Shikoku, Kyushu; very common. Ryukyus, Formosa, China, Korea, Manchuria, and Ussuri.