Japan Flora: Nearly glabrous twining perennial herb with slender rhizomes; stems slender; leaves long-petiolate, sagittate, the lateral lobes (auricles) spreading or slightly deflexed, usually acute and bilobed, the main (central) lobe lanceolate-deltoid, 4-6 cm. long, 3-6 cm. wide, gradually narrowed to tip, obtuse; flowers solitary, axillary, rose, the bracts deltoid-ovate, acute, rounded at base, 1-2 cm. long, longer than the calyx. June-Aug. Sunny grassy places and thickets in lowlands and hills.