Japan Flora: Tuber to 3 cm. across, covered with brown fibers; leaves petioled, deeply 3-lobed to nearly 3-parted, the segments 8-20 cm. long, 2-12 cm. wide, abruptly short-caudate; scape 20-50 cm. long; spathe green outside, typically light purplish within, 4-10 cm. long, the tubular part 2-3 cm. long, the blades broadly lanceolate, obtuse, slightly incurved at tip, smooth outside, densely papillose inside; spadix with a filiform ap­pendage 15-25 cm. long.-- June-Aug.

Honshu (Mino Prov, and westw.), Shikoku, Kyushu.

f. atropurpurea (Makino) Ohwi Spathe dark pur­ple within