Japan Flora: Perennial herb with short rhizomes and several thickened roots; stems elong­ate, scandent in upper portion; leaves verticillate in 4*s or 3’s, spreading, petiolate, ovate, long-acuminate, rounded to broadly cuneate at base, slightly undulate on margin, 5-nerved and with closely parallel, transverse veinlets between the nerves; peduncles axillary, 1- to 2-flowcred, often partly fused to the petiole; flowers erect, half-open, perianth-segments 4, about 12 mm. long, pale green, lanceolate. June.

Introduced and planted for medicinal purposes. China.