Japan Flora: Large, soft perennial with thick, white, short, erect rhizomes; leaves elongate after anthesis, 40-80 cm. long, 15-30 cm. wide, elliptic to narrowly oblong, entire, gradually narrowed at base to a flat petiole, the lateral nerves very slender; scape 10-30 cm. long, tightly covered by the narrow-tubular basal part of the spathe; spathe-blade white, elliptic to ovate, 8-12 cm. long, abruptly acute; spadix terete, cylindric, 4-8 cm. long at anthesis, oblong to short-cylindric, to 12 cm. long and 5 cm. across in fruit; flowers bisexual, perianth­segments small, rounded at apex; anthers yellow, ovoid. May-July. Common in swampy places.

Hokkaido, Honshu (centr. and n. distr.).  Kuriles, Kamchatka, Sakhalin, and Ussuri