Japan Flora: Leaves few from a small tuber, with small bulbils borne at the middle and on the uppermost part of the petiole; leaflets 3, sessile, ovate-elliptic to oblong, 3-12 cm. long, 1-5 cm. wide, entire, glabrous; scape solitary, 20-40 cm. long; spathe typically green, 6-7 cm. long, the tubular part 1.5-2 cm. long, the blade lanceolate, rounded at apex, curved at tip, glabrous outside, puberulent within; spadix with the appendage filiform, erect, 6-10 cm. long, glabrous; berry small, green.  May-July. Cultivated fields and roadsides; Hok­kaido, Honshu, Shikoku, Kyushu; quite common. Korea and China.

f. angustata (Schott) Makino. Leaflets linear.