滇西乌头 dian xi wu tou

Caudex obconical, ca. 3.5 cm. Stem ca. 1.2 m, apically branched, basally sparsely pubescent or becoming glabrous, elsewhere glabrous. Proximal leaves long petiolate; petiole 7--12 cm; leaf blade pentagonal, 9--11 × 13--18 cm, abaxially glabrous, adaxially sparsely pubescent or becoming glabrous, 3-parted; central lobe broadly rhombic; lateral lobes obliquely flabellate, unequally 2-fid slightly beyond middle. Inflorescence terminal, ca. 10-flowered; rachis and pedicels glabrous; proximal bracts leaflike, distal ones lanceolate. Pedicels 3--7 cm, with 2 bracteoles on lowermost pedicels; bracteoles lanceolate, 1.5--1.8 cm, others linear-oblong to linear, 0.6--1.4 cm × 0.6--2.5 mm, glabrous. Sepals purple, abaxially glabrous; lower sepals ca. 1.4 cm; lateral sepals ca. 1.6 cm; upper sepal galeate, 1.6--2 cm high, beak ca. 3 mm, lower margin suberect, oblique upward, 1.7--2.1 cm. Petals glabrous; limb ca. 8 mm; lip ca. 3 mm; spur incurved, ca. 1.8 mm. Stamens glabrous; filaments entire. Carpels 5, glabrous. Fl. Jul--Sep. 2n = 16*.

* Forest margins, by streams; 3200--3500 m. W Yunnan.