叉枝假还阳参 cha zhi jia huan yang shen

Basionym: Geblera akagii Kitagawa, J. Jap. Bot. 13: 430. 1937; Crepidifolium akagii (Kitagawa) Sennikov; C. tenuicaule (Babcock & Stebbins) Tzvelev; Crepis tenuifolia Willdenow subsp. tenuicaulis (Babcock & Stebbins) Handel-Mazzetti; Youngia akagii (Kitagawa) Kitagawa; ?Y. nansiensis Y. Z. Zhao & L. Ma; Y. ordosica Y. Z. Zhao & L. Ma; Y. tenuicaulis (Babcock & Stebbins) Czerepanov; Y. tenuifolia (Willdenow) Babcock & Stebbins subsp. tenuicaulis Babcock & Stebbins.

Shrublets 10-25 cm tall, cushion-forming, rosulate. Taproot woody. Caudex woody, branching with age, densely covered with residues of old leaf bases. Stems many, slender, rigid, hardened, erect, repeatedly, dichotomously, intricately, and divaricately branched almost from base, glabrous. Rosette leaves oblanceolate to narrowly elliptic, 2-8 × 0.5-3 cm, glabrous, pinnatifid to pinnatisect, basally attenuate; lateral lobes 5 or 6 pairs, broadly triangular toothlike to narrowly linear, unequal in length, margin entire, apex acute. Stem leaves few, much smaller, otherwise similar to basal leaves or linear to linear-subulate, reduced in size, undivided, and often bractlike. Synflorescence of each stem divaricately corymbiform, with some capitula. Capitula with 10-12 florets. Involucre narrowly cylindric, 8-9 mm. Phyllaries dark green, abaxially glabrous to slightly puberulent, frequently crested or corniculate below apex; outer phyllaries few, narrowly ovate to lanceolate, longest ca. 2 mm, apex acute; inner phyllaries 8, apex ± obtuse. Achene black to blackish, fusiform, 3.5-5.5 mm, with 10 ribs, shortly scabrid, apex attenuate. Pappus white, 4-6 mm, caducous. Fl. and fr. Jul-Sep. 2n = 42.

Grasslands on mountain slopes, gravelly areas; 1400-4900 m. Gansu, Hebei, Nei Mongol, Xinjiang [Mongolia, E Russia].

Crepidiastrum akagii is superficially similar to and sometimes confused with Askellia flexuosa; for their distinction see there (p. 327). Crepidiastrum akagii is closely related to C. tenuifolium and C. diversifolium and, as was already assumed by Babcock and Stebbins (Publ. Carnegie Inst. Washington 484: 52. 1937), a "polyploid apomict." No material has been seen of Youngia nansiensis, which was provided by its authors with a very poor description and said to be glabrous but otherwise similar to C. akagii (Y. Z. Zhao & L. Ma, Bull. Bot. Res., Harbin 24: 133. 2004); it is provisionally sunk in the synonymy of the latter. The largely neglected Y. alashanica H. C. Fu (in Ma, Fl. Intramongol., ed. 2, 4: 849. 1993), said to have affinities to C. akagii as well, in contrast, is certainly completely unrelated and actually represents with high probability Launaea procumbens (see there, p. 239).