纤细亚菊 xian xi ya ju

Tanacetum gracile J. D. Hooker & Thomson in J. D. Hooker, Fl. Brit. India 3: 318. 1881; Chrysanthemum gracile (J. D. Hooker & Thomson) B. Fedtschenko (1915), not (Schultz Bipontinus) Masferrer y Arquimbau (1881); C. hookeri Kitamura.

Subshrubs, 15-45(-60) cm tall, with thick woody root. Stems strongly branched at base and woody for much of length, densely grayish pubescent, hairs adpressed, bifid. Lower stem leaves withered at anthesis. Middle stem leaves 2-3 cm; petiole rather long, wingless, base sometimes with linear pseudostipules; leaf blade rounded triangular, ca. 2.5 cm wide, both surfaces gray-green, appressed pubescent, twice ternately divided; ultimate segments oblong to linear, to 1.5 mm wide. Upper stem leaves reduced, subsessile, 3-5-lobed. Synflorescence a terminal flat-topped panicle. Capitula 20-60. Involucres 2.5-3 mm in diam.; phyllaries herbaceous, abaxially subglabrous, scarious margin broad, light or brown, apex broadened, middle and inner phyllaries 2-3 × as long as outer, to 4 mm. Florets 15-25, corolla tubular; marginal female florets few; disk florets: corolla 1.5-2 mm. Achenes 1.2-1.5 mm.

Stony slopes; above 3000 m. Ningxia, Xizang [Kyrgyzstan, Tajikistan (Pamirs)].