单头亚菊 dan tou ya ju

Tanacetum scharnhorstii Regel & Schmalhausen, Trudy Imp. S.-Peterburgsk. Bot. Sada 5: 620. 1878; Chrysanthemum scharnhorstii (Regel & Schmalhausen) B. Fedtschenko; Hippolytia scharnhorstii (Regel & Schmalhausen) Poljakov.

Subshrubs, 4-10 cm tall, with thick woody rootstock ca. 2 cm in diam. Flowering and sterile branches gray-white, densely and thickly pubescent. Petiole 1-2 mm; leaf blade suborbicular or flabelliform, 3-5 × 5-6 mm, both surfaces gray-white, densely pubescent, bipalmatisect; primary lateral segments 3-7; ultimate segments ovate or elliptic, apex obtuse or rounded. Synflorescence a solitary terminal capitulum. Involucres campanulate, 7-10 mm in diam.; phyllaries in 4 rows, scarious margin brown, outer ones ovate, ca. 3 mm, abaxially sparsely pubescent, middle and inner ones broadly elliptic to oblanceolate, 3-5 mm, middle ones sparsely pubescent abaxially, inner ones glabrous abaxially. Florets yellow; marginal female florets 5, corolla narrowly tubular, ca. 2.5 mm, apex 3- or 4-denticulate; disk florets many, corolla tubular, ca. 3.5 mm. Achenes ca. 2 mm. Fl. and fr. Jul-Aug.

● Fissures of rocks on mountain slopes, calcareous talus slopes, thickets; 3900-5100 m. Gansu, Qinghai, Xinjiang (C Tian Shan), Xizang.