Japan Flora: Leaf­lets to 17, obovate, to 8 cm. long, 3.5-4 cm. wide, abruptly short-acuminate; spathe dark purple, without stripes, the blade deltoid-ovate, gradually tapering to apex, scarcely auricled on the upper margins of the long cylindrical tube; spadix-appendage prominently thickened at tip; otherwise with the characters of A, ovale Nakai.     

Tuber rather small, about 15 mm. across; leaf solitary, the petiole terete, about 20 cm. long; leaflets 7-9, oblong to obovate-oblong, abruptly acuminate, cuneate at base, the terminal one 10-12 cm. long, 4-5 cm. wide; peduncle about 20 cm. long; spathe purplish, the auricles rather narrow, the blade 12-14 cm. long, oblong-ovate, abruptly long-acuminate, strongly declined over the spadix, the spadix-appendage stout, cylindric-clavate, slightly thickened at apex, truncate at base, about 8 mm. in diameter at apex.  May. 

Honshu (Izu Penin., Suwo).