Actaea japonica Thunberg in Murray, Syst. Veg., ed. 14, 488. 1784; A. acerina Prantl, nom. illeg.; A. purpurea (P. K. Hsiao) J. Compton; Cimicifuga acerina Tanaka, nom. illeg.; C. acerina f. hispidula P. K. Hsiao; C. acerina f. purpurea P. K. Hsiao; C. acerina f. strigulosa P. K. Hsiao; C. japonica var. acerina Huth; C. macrophylla Koidzumi; C. purpurea (P. K. Hsiao) C. W. Park & H. W. Lee; Pityrosperma acerinum Siebold & Zuccarini, nom. illeg. (included A. japonica ).

Rhizome blackish, with numerous fibrous roots. Stems erect, 25--110 cm tall, basally subglabrous or sparsely spreading villous, apically densely gray pubescent. Basal leaves 1 or 2, ternate, long petiolate; petiole to 32 cm, sparsely villous or subglabrous; leaf blade to 35 cm. Leaflet petiolate; petiolules 4--12 cm; terminal leaflet ovate-cordate, 5--20 × 4--18 cm, palmately 7--9-lobed, lobes triangular or obliquely trapezoid, margin serrate; lateral leaflets smaller than terminal one, abaxially white pubescent at veins, adaxially subglabrous except shortly strigose at margin. Inflorescence spicate, terminal, simple or 1--3-branched, 10--25 cm; rachis densely gray pubescent; bracts 3-parted or triangular. Flowers subsessile, small, ca. 4 mm in diam. Sepals white or purple, elliptic to obovate-elliptic, 3--5 mm. Petals orbicular-ovate, 4--4.5 mm, with a nectary at base. Filaments narrowly linear, 4--7 mm; anthers ellipsoid, 1--1.5 mm. Carpels 1, sometimes 2, glabrous. Follicles ca. 1 cm × 3 mm. Seeds 8--12, pale brown, ellipsoid-ovoid to globose, ca. 2.5 mm, adaxially with numerous short scaly wings. Fl. Aug--Sep, fr. Oct. 2n = 16*.

Forests, forest margins; 800--2600 m. Anhui, Gansu, N Guangdong, Guizhou, SW Hebei, S Henan, Hubei, Hunan, Jiangxi, S Shaanxi, S Shanxi, Sichuan, Yunnan, Zhejiang [Japan, Korea].