白术 bai shu

Atractylis macrocephala (Koidzumi) Nemoto (1936), not Desfontaines (1799); A. macrocephala var. hunanensis Y. Ling.

Herbs 20-60 cm tall. Rhizome thick. Stem branched from base, glabrous. Leaves papery, glabrous. Middle cauline leaves petiolate; petiole 3-6 cm; leaf blade divided almost to base into 3-5 segments; lateral segments entire or bipartite, oblanceolate to ± narrowly elliptic, 4.5-7 × 1.5-2 cm; terminal segment largest. Upper cauline leaves similar but smaller. Outer bracts sessile, elliptic to narrowly elliptic, margin entire; inner bracts pinnatisect. Capitula 6-10. Involucre broadly campanulate, 3-4 cm in diam. Phyllaries numerous, imbricate, margin white cobwebby, apex obtuse; outer phyllaries ovate to triangular, 6-8 × 3-4 mm; innermost phyllaries lanceolate to broadly linear, 11-20 × 2-3 mm. Corolla purplish red, ca. 1.7 cm. Achene obconic, ca. 7.5 mm, hairs white. Pappus dirty white, ca. 1.7 cm. Fl. and fr. Aug-Oct. 2n = 24*.

● Grasslands, forests; 600-2800 m. W Anhui, Chongqing, N Fujian, Guizhou, Hubei, Hunan, W Jiangxi, Zhejiang.

Atractylodes macrocephala is cultivated throughout China. The rhizomes are used medicinally.