Taraxacum subg. Ixeris Cassini, Bull. Sci. Soc. Philom. Paris 1821: 173. 1821; Chorisis Candolle; Chorisma D. Don (1829), not Lindley ex Sweet (1821).
Herbs, annual or perennial, often rosulate. Stems ± erect, sometimes also long creeping and with erect flowering branches. Synflorescence usually corymbiform. Capitula with (12-)15-25(-40) florets. Involucre cylindric to narrowly campanulate. Phyllaries in several series, glabrous; outer phyllaries several, longest 1/4-1/2 as long as inner ones; inner phyllaries usually 8, linear-lanceolate to lanceolate, equal in length, glabrous, margin usually scarious. Receptacle naked. Florets yellow, rarely whitish or purplish. Achene brown, ± fusiform, not compressed, with 10 (5 main ribs alternating with 5 ± equal secondary ribs) very prominent ± winglike ribs, space between ribs narrowly V- or U-shaped, apex contracted or attenuate into a filiform or slender beak. Pappus white, bristles scabrid.
About eight species: E and S Asia; six species in China.
The revised circumscription of Ixeris employed here follows the treatment by Pak and Kawano (Mem. Fac. Sci. Kyoto Univ., Ser. Biol. 15: 29-61. 1992), based on carpological and karyological investigations, which also includes the former monotypic Chorisis accommodating I. repens. Pak and Kawano’s concept of the genus has been corroborated recently in molecular phylogenetic analyses of subtribe Crepidinae by J. W. Zhang et al. (in prep.). Its basic chromosome number is x = 8.