乌头 wu tou

Caudex obconical, 2--4 cm, 1--1.6 cm in diam. Stem 0.6--1.5(--2) m, branched, apically sparsely retrorse pubescent, with leaves equally arranged along stem. Proximal cauline leaves withered at anthesis; middle ones long petiolate; petiole 1--2.5 cm; leaf blade pentagonal, 6--11 × 9--15 cm, thinly leathery, papery, or herbaceous, abaxially sparsely pubescent or densely pubescent at veins, adaxially sparsely appressed pubescent, base slightly cordate, 3-sect or nearly to base; central segment broadly rhombic, sometimes obovate-rhombic or rhombic; lateral segments unequally 2-parted. Inflorescence terminal, 6--10(--25) cm, many flowered; rachis and pedicels ± densely retrorse and appressed pubescent, or spreading pubescent; proximal bracts 3-fid, others narrowly ovate to lanceolate. Pedicels 1.5--3(--5.5) cm, with 2 bracteoles at middle or below; bracteoles lanceolate to linear, 3--5(--10) × 0.5--0.8(--2) mm. Sepals blue-purple, abaxially pubescent; lower sepals 1.5--1.7 cm; lateral sepals 1.5--2 cm; upper sepal high galeate, 2--2.6 cm high, 1.7--2.2 cm from base to beak, lower margin slightly concave. Petals glabrous; limb ca. 1.1 cm; lip ca. 6 mm, slightly concave; spur usually circinate, (1--)2--2.5 mm. Stamens glabrous or sparsely pubescent; filaments 2-denticulate, or entire. Carpels 3--5, sparsely or densely pubescent, rarely glabrous. Follicles 1.5--1.8 cm. Seeds 3--3.2 mm. Fl. Sep--Oct. 2n = 32*, 48*, 64*.

Forest margins, scrub, grassy slopes, mountains; 100--2200 m. Anhui, Fujian, SE Gansu, N Guangdong, N Guangxi, Guizhou, Hebei, S Henan, W Hubei, Hunan, Jiangsu, Jiangxi, S Liaoning, Nei Mongol, S and SW Shaanxi, Shandong, Shanxi, Sichuan, Yunnan, Zhejiang [N Vietnam].

Further study is necessary to determine the placement of Aconitum carmichaelii var. angustius W. T. Wang & P. K. Hsiao (in W. T. Wang, Acta Bot. Yunnan. 15: 349. 1993).