长枝乌头 chang zhi wu tou

Tuber carrot-shaped, ca. 5 cm, ca. 8 mm in diam. Stem trailing, ca. 1.8 m, with slender branches to 34 cm, basally glabrous, apically pubescent. Cauline leaves with petiole ca. 2.5 cm; leaf blade ovate-pentagonal, to 9 × 9 cm, abaxially glabrous, adaxially sparsely appressed pubescent, 3-parted; central lobe ovate-rhombic, apex caudate-acuminate, subpinnately parted, lobules narrowly ovate; lateral lobes obliquely flabellate, unequally 2-fid. Inflorescence terminal, ca. 30 cm, many flowered; rachis and pedicels sparsely spreading pubescent and glandular pubescent; proximal bracts leaflike, distal ones linear. Pedicels 3--5 cm, with 2 bracteoles at middle; bracteoles narrowly linear or subulate, 3--8 mm. Sepals blue-purple, abaxially glabrous; lower sepals ca. 9 mm; lateral sepals 1.2--1.4 cm; upper sepal falcate-navicular, 1.4--1.8 cm from base to beak. Petaline claw sparsely pubescent; lip ca. 3.5 mm; spur ca. 1.2 mm. Stamens glabrous; filaments entire. Carpels 4 or 5(or 6), glabrous. Fl. Aug--Sep.

* Mountains; ca. 3700 m. W Sichuan.