Japan Flora: Tuber depressed-globose; pseudostem 5-20 cm. long; leaves 2, the petiole terete, 7-12 cm. long; leaflets 3-5, obovate, oblong, or elliptic, 5-20 cm. long，3-10 cm. wide, abruptly short- acuminate; peduncle 5-12 cm. long; spathe dark purple, the upper margins of the tube not recurved, the blade obliquely ascending, narrowed toward base, elliptic, 8-13 cm. long, 4-5 cm. wide, abruptly long-acuminate; spadix-appendage thick- cylindric, whitish, 6 mm. wide, capitately thickened at apex forming a globose head 10-18 mm. across.  May-June.

Honshu (Yamato), Shikoku, Kyushu.