大渡乌头 da du wu tou

Caudex carrot-shaped, ca. 6 mm, ca. 1.2 cm in diam. Stem to 1.2 m, branched, sparsely retrorse and appressed pubescent, with leaves equally arranged along stem. Proximal cauline leaves withered at anthesis, middle ones slightly long petiolate; petiole 3--4 cm, sparsely retrorse pubescent; leaf blade cordate-pentagonal, ca. 7.5 × 8.5 cm, nearly glabrous or sparsely pubescent, 3-parted; central lobe rhombic; lateral lobes obliquely flabellate, unequally 2-fid. Inflorescence terminal, 10--35 cm, 7--20-flowered; rachis and pedicels retrorse or spreading pubescent, or intermixed with short glandular hairs, or glabrous; proximal bracts leaflike, shortly stipitate, distal ones linear, ca. 9 mm. Pedicels 1--10 cm, with 2 bracteoles at middle; bracteoles of proximal pedicels to 1.5 cm, 3-fid; others oblong to linear, 4--10 × 0.5--2 mm, nearly glabrous, undivided. Sepals blue, abaxially glabrous; lower sepals ca. 20 cm; lateral sepals ca. 2.1 cm; upper sepal galeate, 1.8--2.4 cm high, 1.9--2.3 cm from base to beak, external margin suberect or oblique, lower margin slightly oblique upward, suberect or slightly concave. Petals glabrous; claw erect or geniculate at apex; limb ca. 5 mm; spur short, beak curved or subcircinate. Stamens glabrous; filaments entire or 2-denticulate. Carpels 3 or 5, glabrous. Fl. Jul--Aug.

* Grassy slopes, forests; 3400--4100 m. Sichuan.