5. Ixeris chinensis (Thunberg) Kitagawa, Bot. Mag. (Tokyo). 48: 113. 1934.
中华苦荬菜 zhong hua ku mai cai
Herbs 5-50 cm tall, perennial, rosulate, glabrous. Taproot, often with shoot-bearing lateral roots. Stems usually few to several, rarely solitary, ascending-erect to erect, branched from base or higher up. Rosette leaves oblanceolate, elliptic, narrowly elliptic, or ± linear, 6-24 × 1-2 cm, undivided or pinnatifid to pinnatipartite, basally attenuate, margin entire or sinuate-dentate, apex obtuse, acute, or attenuate; lateral lobes 2-7 pairs, narrowly triangular, linear-triangular, or linear. Stem leaves (0 or)1-4, narrowly lanceolate to linear-lanceolate, mostly undivided or more rarely pinnatifid, base semiamplexicaul and usually not or rarely with a basal pair of sideward directed clasping lobes, margin entire, apex acuminate. Synflorescence laxly corymbiform, with few to many capitula. Capitula with 15-25 florets; peduncle wiry, ca. 1 to several cm. Involucre cylindric, 6-11 mm. Phyllaries abaxially glabrous, apex acute; outer phyllaries ± ovate, longest 1-1.5 mm; inner phyllaries 8. Florets bright yellow, pale yellow, white, or purplish. Anther tube and style greenish to blackish upon drying. Achene brown, subfusiform, 4-6 mm, apex attenuate into a slender 2.5-3 mm beak. Pappus ca. 5 mm. Fl. and fr. Jun-Oct.
Grasslands on mountain slopes, forests, forest margins, along rivers, ravines, open areas, degraded shrublands, thickets, riverbanks, rock crevices, sandy soil areas, fields, field margins, wastelands, roadsides; below 100-4000 m. Anhui, Chongqing, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Hainan, Hebei, Heilongjiang, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Taiwan, Xinjiang, Xizang, Yunnan, Zhejiang [?Cambodia, Japan, Korea, Laos, Mongolia, E Russia, ?Thailand, Vietnam].
Ixeris chinensis includes diploid, triploid, and tetraploid cytotypes. Pak et al. (Acta Phytotax. Geobot. 48: 187-196. 1997) have shown that all three cytotype are present in mainland Asia, while in Taiwan only the diploid cytotype and in Japan only the triploid and tetraploid cytotypes occur. Otherwise, all three cytotypes frequently seem to occur sympatrically. The triploid and tetraploid cytotypes have been identified with I. chinensis subsp. strigosa (see Kitamura, Mem. Coll. Sci. Kyoto Imp. Univ., Ser. B, Biol. 23: 112-116. 1956), which has long involucres (9-10 mm) and achenes as well as whitish or pale purplish florets. The diploid cytotype has been identified with I. chinensis subsp. chinensis, which has involucres of 6-8 mm and yellow florets. The third subspecies recognized by Kitamura, I. chinensis subsp. versicolor (sometimes even treated as two separate species, I. graminea and I. graminifolia, see, e.g., under Ixeridium, in Tzvelev, Fl. URSS 29: 388-392. 1964; Rast. Tsentral. Azii 14b: 62-65. 2008) appears rather to include forms intermediate between the former two at least with respect to involucre length (8-9 mm) and floret color (variably yellow, white, or purplish). It was not included in the analysis by Pak et al. (loc. cit.) and is little understood, even with respect to its actual delimitation from I. chinensis subsp. strigosa. Until further studies, such as started by Pak et al. (loc. cit.), are available that also include I. chinensis subsp. versicolor, the taxonomy of I. chinensis remains unsatisfactory. For the time being, it appears appropriate basically to maintain the classification of Kitamura (loc. cit. 1956) with three subspecies, the delimitation between them, however, not being clear-cut, and especially between I. chinensis subsp. versicolor and I. chinensis subsp. strigosa often questionable in material from China. The distribution ranges given below should therefore be taken with great caution. Leaf shape is very variable in I. chinensis; this variation, however, follows patterns not unusual in the genus and the tribe and is taxonomically of no value.