6. Askellia flexuosa (Ledebour) W. A. Weber, Phytologia. 55: 6. 1984.
弯茎假苦菜 wan jing jia ku cai
Prenanthes polymorpha Ledebour var. flexuosa Ledebour, Fl. Altaic. 4: 145. 1833; ?Askellia melanthera (C. H. An) Tzvelev; Barkhausia flexuosa (Ledebour) Candolle; B. flexuosa var. lyrata Schrenk; Crepis flexuosa (Ledebour) C. B. Clarke; ?C. melanthera C. H. An; Hieracioides flexuosa (Ledebour) Kuntze; Youngia flexuosa (Ledebour) Ledebour; Y. flexuosa var. gigantea C. Winkler ex O. Fedtschenko; Y. glauca Edgeworth.
Herbs 3-30 cm tall, perennial, glaucescent, glabrous. Roots and subterranean shoots often branched and slender. Caudex sometimes branched in older plants, with rosette leaves often well developed. Stem repeatedly divaricately and often intricately branched from base; branches few to numerous, usually rather delicate, ascending. Basal and lower stem leaves extremely variable, oblanceolate, ovate, elliptic, lanceolate, or more rarely linear, 2-8 × 0.2-2 cm, shallowly pinnatifid to pinnatisect or more rarely undivided, base attenuate into a 0.5-1.5 cm petiole-like portion, margin entire to sinuate-dentate, apex acute to rounded; lateral lobes (if present) (1-)3-5-paired, opposite or alternate, elliptic, linear, or toothlike, rarely pinnately divided. Middle and upper stem leaves similar to lower stem leaves but sessile or shortly petiolate and linear-lanceolate to narrowly linear, upward on stem gradually smaller. Synflorescence of each branch corymbiform and sometimes very densely so, with few to several capitula. Capitula with 9-13 florets; peduncle filiform, extremely variable in length and ranging from much longer than involucre to almost absent. Involucre narrowly cylindric, 6-10 × 2-3 mm. Phyllaries green, abaxially glabrous; outer phyllaries ovate to ovate-lanceolate, longest usually ca. 2 mm, apex acute to obtuse; inner phyllaries 8, margin narrow and scarious, apex acute to obtuse. Florets yellow. Corolla 0.9-1.1 cm. Anther tube 3-4 mm. Achene pale yellow, fusiform, 4-6 mm, apex attenuate. Pappus 4-6 mm. Fl. and fr. Jun-Oct. 2n = 14*.
Stream banks, lake margins, marshes and floodplains, sandy areas, gravel and loess areas, rather sparsely covered mountain slopes, rocky outcrops, alpine meadows; 800-5100 m. Gansu, Nei Mongol, Ningxia, Qinghai, Shanxi, Xinjiang, Xizang [Afghanistan, Kashmir, Kazakhstan, Kyrgyzstan, Mongolia, Nepal, Pakistan, SC Russia, Tajikistan; SW Asia].
Askellia flexuosa is the most widespread and frequent species of the genus in China, with a considerable ecological amplitude. The species is superficially similar to Crepidiastrum akagii, but the latter differs by its blackish achene, with acute antrorse papillae and less attenuate apex, and its somewhat thicker involucre, with outer phyllaries somewhat longer.
Askellia melanthera (= Crepis melanthera), only known from the type (not seen) collected in a schoolyard of the city of Ürümqi, Xinjiang, poorly described and diagnosed by blackish anthers and style branches, may perhaps otherwise match A. flexuosa and is tentatively included here.