1. Sonchus brachyotus Candolle, Prodr. 7: 186. 1838.
长裂苦苣菜 chang lie ku ju cai
Sonchus arenicola Voroschilov; S. arvensis Linnaeus subsp. arenicola (Voroschilov) Voroschilov; S. arvensis f. brachyotus (Candolle) Kirpicznikov; S. arvensis subsp. brachyotus (Candolle) Kitamura; S. brachyotus var. potaninii Tzvelev; S. cavaleriei H. Léveillé; S. chinensis Fischer; S. fauriei H. Léveillé & Vaniot; S. taquetii H. Léveillé.
Herbs 30-100 cm tall, perennial. Taproot with shoot-bearing lateral roots. Stem usually unbranched below synflorescence, glabrous. Basal and lower stem leaves narrowly elliptic to oblanceolate, 5-20 × 1-3(-5) cm, undivided or rarely pinnatifid to pinnatipartite, glabrous, base semiamplexicaul to shortly auriculately clasping, margin denticulate and often sinuate-dentate, apex rounded, obtuse, or subacute; lateral lobes triangular to narrowly triangular if any. Middle and upper stem leaves similar to lower leaves but smaller. Synflorescence corymbiform, with few to several capitula. Capitula with very many (usually 170-300) florets; peduncle 0.5-7 cm, slender, glabrous or more rarely white tomentose apically and glabrescent. Involucre broadly campanulate, ca. 1.5 cm, glabrous or more rarely basally faintly white tomentose. Phyllaries mostly glabrous, apex acute; outer phyllaries triangular-ovate to lanceolate, 1.5-3 mm wide. Corolla 1.6-2.6 cm. Achene narrowly ellipsoid, 2-4 mm, subcompressed, with 1-3 main ribs on either face, weakly rugose. Pappus 1.1-1.2 cm, persistent. Fl. and fr. May-Sep. 2n = 18.
Grassy slopes in mountains, by rivers, alkaline areas; 300-4000 m. ?Fujian, Gansu, Guangdong, Guangxi, Hebei, Heilongjiang, Henan, ?Hunan, Jiangsu, Jiangxi, Jilin, Liaoning, Nei Mongol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang, Xizang, Yunnan, ?Zhejiang [Japan, Kazakhstan, Kyrgyzstan, Mongolia, SE Russia, Thailand].
The diploids Sonchus brachyotus and S. wightianus together with the diploid Mediterranean and SW to C Asian S. maritimus Linnaeus and the chiefly European polyploid S. arvensis Linnaeus (see also note under S. wightianus) form a group of closely related species. Identity and delimitation of S. brachyotus, S. wightianus, and S. arvensis (incl. S. uliginosus M. Bieberstein) had long been misunderstood, before Boulos (Bot. Not. 126: 155-196. 1973) clarified their taxonomy. Due to the confusion in the past, the distribution of S. brachyotus in China is probably still incompletely known. Two conceptual problems surrounded this species. 1) The name S. transcaspicus Nevski was applied (e.g., FRPS 80(1): 66. 1997) for plants of this group with glabrous, non-glandular involucres and undivided leaves, and that species was considered as widely distributed in China, except for the southeast. Sonchus transcaspicus, however, is a name coined for C Asian populations of S. maritimus (see, e.g., Kirpicznikov, Fl. URSS 29: 244-260. 1964). The alleged minor differences in leaf shape are not consistent and do not justify the recognition of two taxonomic entities, as has been concluded already by Boulos (loc. cit.) and more recently confirmed by Sennikov (Bot. Zhurn. 85(12): 90-94. 2000). The easternmost occurrences of S. maritimus/S. transcaspicus are in Tajikistan and Kyrgyzstan (according to Sennikov, loc. cit.) or, more likely, even further west in E Turkmenistan (Boulos, loc. cit.; Tzvelev, Rast. Tsentral. Azii 14b: 77. 2008). The species is also not given in the treatment of Sonchus for the immediately adjacent Chinese province of Xinjiang (C. H. An, Fl. Xinjiang. 5: 434-438. 1999). Sonchus transcaspicus sensu FRPS (80(1): 66. 1997) instead refers to the frequent undivided-leafy form of S. brachyotus. The latter species, like S. arvensis and in contrast to S. maritimus, does not actually have a rhizome, although often stated in the literature, but has lateral roots that produce new shoots even after the root system has been fragmented. Moreover, S. maritimus/S. transcaspicus is a species with glaucous leaves, smaller capitula with 80-150 florets, a corolla with the tube much shorter than the ligule, achene of 2-3 mm only, and a caducous pappus. 2) The name S. uliginosus has been applied (e.g., FRPS 80(1): 68. 1997) for plants of this group with glabrous, non-glandular involucres and pinnately lobed leaves with broadly triangular-obovate to semiorbicular lateral lobes. For the most part, this includes plants of S. wightianus (also referred to as S. wightianus subsp. wallichianus). Some records, however, from the northern provinces especially, apparently refer to the rarer pinnately leafy form of S. brachyotus.