Japan Flora: Stems 20-70 cm. long, usually simple; leaves membranous, acuminate at both ends, 10-20 cm. long, 2.5-6 cm. wide; calyx-teeth deltoid, obtuse; petals broadly obovate, about 3 mm. long; capsules broadly ovoid, about 4 mm. long inclusive of the styles; styles 3; seeds small, elliptic, with a very short wing at each end. July-Sept. Woods in mountains;
Honshu (Kanto Distr. and westw.), Shikoku, Kyushu.