齿叶蓍 chi ye shi

Ptarmica acuminata Ledebour, Fl. Ross. 2: 529. 1845; Achillea ptarmica Linnaeus var. acuminata (Ledebour) Heimerl; A. ptarmica var. angustifolia Heimerl.

Herbs, perennial, 30-100 cm tall; stems solitary, erect, corymbosely branched, lower part glabrous, upper part densely pubescent. Basal and lower stem leaves withered by anthesis. Middle stem leaves sessile; leaf blade lanceolate or linear-lanceolate, 3-8(-11) × 0.4-0.9 cm, both surfaces pubescent at first, glabrescent or pubescent along veins abaxially, base slightly attenuate, margin double-serrulate, apex acuminate. Synflorescence a lax terminal flat-topped panicle. Capitula rather many. Involucres hemispheric, ca. 5 × 9 mm; phyllaries in 3 rows, scarious margin broad, yellowish or brownish, outer short, ovate-oblong, apex acute, inner ones oblong, apex rounded. Paleae similar to phyllaries, upper part and apex yellow villous. Ray florets 10-23; lamina white, 3-8 × 2.5-5.5 mm, apex 3-crenate. Disk florets white, tubular. Achenes oblanceolate, 2.5-3 × ca. 1.5 mm, with white lateral ribs. Corona absent. Fl. and fr. Jul-Aug.

Moist places on mountain slopes, meadows, forest margins; 500-2900 m. Gansu, Hebei, Henan, Jilin, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shanxi [Japan, Korea, Mongolia, Russia].