膝瓣乌头 xi ban wu tou

Caudex unknown. Stem ca. 1 m tall, branched, glabrous, or yellowish spreading pubescent. Proximal cauline leaves long petiolate; petiole 3--5 cm, glabrous, base sheathed; leaf blade orbicular-pentagonal, 6--10 × 6--10 cm, adaxially sparsely appressed pubescent at veins, base cordate, 3-parted; central lobe rhombic, 3-fid; lateral lobes obliquely flabellate, 2-parted beyond middle. Inflorescence racemose or corymbose, 3--8.5 cm, 2--8-flowered; rachis and pedicels glabrous; bracts leaflike. Pedicel 2--4 cm, with 2 bracteoles at middle; bracteoles linear, 3.5--4.5 mm, glabrous. Sepals blue, abaxially glabrous; lower sepals oblong; lateral sepals broadly obovate, 1.3--1.4 cm, abaxially sparsely pubescent; upper sepal high galeate, ca. 1.6 cm high, lower margin 1.5--1.8 cm. Petals glabrous; claw geniculate at apex; limb ca. 1.1 cm; lip 4.5--5.5 mm, 2-lobed at apex; spur incurved or circinate, 2.5--4.5 mm. Stamens glabrous; filaments entire or 2-denticulate. Carpels 5, glabrous. Fl. Jul. 2n = 16*.

* Mountains, grassy slopes, wet grassy places, by streams; 3200--3600 m. Sichuan, Yunnan.