细叶亚菊 xi ye ya ju

Tanacetum tenuifolium Jacquemont ex Candolle, Prodr. 6: 129. 1838; Ajania roborowskii Muldashev; ?A. roborowskii var. tsinghaica Muldashev; Chrysanthemum roborowskii (Muldashev) H. Ohashi & Yonekura; ?C. roborowskii var. tsinghaicum (Muldashev) H. Ohashi & Yonekura; C. stenolobum Handel-Mazzetti.

Herbs, perennial, 9-25 cm tall; rhizomes slender, with slender fibrous roots. Stems many, procumbent and erect; procumbent stems with many brown ovate cataphylls; erect stems branched from base, upper parts and peduncles appressed pubescent, hairs medifixed. Middle stem leaves: petiole 0.4-0.8 cm; leaf blade suborbicular, triangular-ovate, or flabelliform, 1-2 × 1-2 cm, abaxially white or gray-white, densely appressed villous, adaxially pale green, sparsely villous, 2-pinnatisect; primary lateral segments 2- or 3-paired; ultimate segments narrowly elliptic or oblanceolate. Proximal and distal stem leaves gradually smaller. Synflorescence a terminal flat-topped cyme, 2-3 cm in diam. Capitula few. Involucres campanulate, ca. 4 mm in diam.; phyllaries in 4 rows, apex obtuse, scarious margin distinctly divided into dark brown inner zones and narrow colorless outer zone, outer ones lanceolate, ca. 2.5 mm, abaxially sparsely pubescent, middle and inner ones elliptic to oblanceolate, 3-4 mm, abaxially glabrous. Florets dark or orange yellow, exterior with sessile glands; marginal female florets 7-13, corolla narrowly tubular, ca. 2 mm, apex 2- or 3-denticulate; disk florets 30-60, corolla 3-4 mm. Achenes ca. 1 mm. Fl. and fr. Aug-Oct. 2n = 36*.

● Grasslands on mountain slopes; 2200-4600 m. Gansu, Jiangsu, Qinghai, Sichuan, Xizang, Yunnan.

Ajania roborowskii var. tsinghaica is known to us only from the protologue. It appears to be a depauperate form with less divided leaves.