Japan Flora: Plant herbaceous, much branched; stems striate; leaves relatively thick, rather firm, slightly lustrous above, paler beneath, ovate or ovate-oblong, 5-15 cm. long, 2.5-7 cm. wide, short-acuminate, usually cordate or sometimes rounded at base, 5- to 7-nerved, glabrous, rarely with papillae on slightly raised veinlets beneath, the petioles 5-25(-30) mm. long, tendril-bearing; umbels many-flowered, simple, axillary, the pedicels 7-12 mm. long, the staminate tepals recurved, lanceolate, about 4 mm. long, the stamens 2/3-4/5 as long as the tepals; anthers about 1.5 nun. long; staminodes absent in the pistillate flowers. July-Aug.

Hokkaido, Honshu, Shikoku, Kyushu.

f. stenophylla (Hara) T. Koyama. A narrow-leaved phase.