黄草乌 huang cao wu

Caudex ellipsoid-globose or carrot-shaped, 2.7--7 cm, ca. 1 cm in diam. Stem twining, to 4 m, branched, sparsely retrorse pubescent or nearly glabrous. Leaves with petiole 5--10 cm; leaf blade papery, abaxially sparsely pubescent at veins, base broadly cordate, 3-sect or nearly to base; central segment broadly rhombic, apex acute or shortly acuminate; lateral segments obliquely flabellate, unequally 2-parted slightly beyond middle. Inflorescence 3--6-flowered; rachis and pedicels densely retrorse yellowish pubescent or spreading pubescent; bracts linear. Pedicels 2--4 cm, with 2 bracteoles at middle or below; bracteoles narrowly linear, 3--5 × 0.3--0.5 mm, densely pubescent. Sepals purple-blue, abaxially densely pubescent; lower sepals ca. 1.3 cm; lateral sepals 1.3--1.4 cm; upper sepal 1.5--1.6 cm high, shortly beaked. Petals glabrous; lip ca. 6 mm, slightly concave; spur incurved, ca. 3 mm. Stamens glabrous; filaments entire or 2-denticulate. Carpels 5, glabrous or ovary sparsely pubescent at upper part. Follicles erect, 1.6--1.8 cm, glabrous. Seeds ca. 3 mm. Fl. Aug--Oct. 2n = 16*.

* Scrub, mountains; 2100--3000 m. W Guizhou, SW Sichuan, C and N Yunnan.