五叉沟乌头 wu cha gou wu tou

Caudex obconical, ca. 7 cm, ca. 1 cm in diam. Stem 90--110 cm, sparsely appressed and retrorse pubescent. Proximal cauline leaves long petiolate, withered at anthesis, distal ones shortly petiolate; petiole 1--3 cm; leaf blade pentagonal, 6--10 × 7--12 cm, abaxially glabrous, adaxially retrorse pubescent, palmately 3-sect; central segment rhombic, apex acuminate, subpinnately parted; lateral segments obliquely flabellate, unequally 2-parted. Inflorescence terminal, many flowered; rachis and pedicels glabrous; proximal bracts leaflike, distal ones linear. Pedicels 1--3 cm, distally with 2 bracteoles; bracteoles linear, 5--7 mm. Sepals yellowish, abaxially pubescent; upper sepal oblong, ca. 1.4 × 0.5--0.8 cm. Petals glabrous, ca. 1.6 cm; limb 3--4 mm wide; lip ca. 6 mm, 2-lobed at apex; spur incurved, 1--2 mm. Stamens glabrous; filaments 1- or 2-denticulate. Carpels 5, glabrous. Fl. Aug.

* Forest margins; ca. 900 m. Nei Mongol (Hinggan Meng).