川甘岩参 chuan gan yan shen

Lactuca roborowskii Maximowicz, Bull. Acad. Imp. Sci. Saint-Pétersbourg 29: 177. 1883; Chaetoseris albiflora Tzvelev; C. potaninii Tzvelev; C. prattii (Dunn) Tzvelev; C. roborowskii (Maximowicz) C. Shih; L. prattii Dunn.

Herbs 20-90 cm tall, perennial. Rhizomes very short. Stem solitary, erect, apically branched and glabrous or with white, stiff, subulate, and partly glandular hairs. Basal and lower leaves with winged clasping petiole to 10(-15) cm; leaf blade narrowly obovate to elliptic, 4.5-16 × 1.5-6 cm, pinnatipartite to pinnatisect or lyrately so, glabrous, margin entire or with few larger teeth; lateral lobes 2-7 pairs, lanceolate, elliptic, or linear, recurved, apex acute to obtuse; terminal lobe triangular-ovate, ovate-sagittate, linear, or lanceolate, apex acute to obtuse. Middle and upper stem leaves shortly petiolate or sessile; leaf blade elliptic to lanceolate, smaller, narrower, and less divided than lower leaves, base sagittately to auriculately clasping. Synflorescence paniculiform, with numerous capitula. Capitula with 10-12 florets. Involucre narrowly cylindric, (8-)9-10(-12) × 3-4 mm. Phyllaries glabrous or with subulate hairs, apex acute to obtuse; outer phyllaries triangular-ovate to linear-lanceolate, longest ca. 3/4 as long as inner phyllaries; inner phyllaries 8. Florets blue to purplish blue, rarely white. Achene 4-5 mm; body dark reddish to blackish brown, ellipsoid, compressed, with broad lateral ribs; beak greenish to brownish, 1-1.5 mm, slender. Pappus double, outer hairs ca. 0.2 mm, bristles ca. 7 mm. Fl. and fr. Jul-Sep.

● Thickets, grasslands; 1900-4200 m. Gansu, Ningxia, Qinghai, Sichuan, Xizang.

Chaetoseris albiflora, with white florets and strongly recurved leaf lobes, recently described from Xizang, hardly deserves recognition as a separate taxon and is here placed in the synonymy of Cicerbita roborowskii. Another recently described species from Xizang and based on a single 19th century collection, Chaetoseris potaninii is said to be closely related to Cicerbita roborowskii but to have a strongly reduced outer pappus and leaves with only 1-3 pairs of lateral lobes each with 1 or 2 large teeth. As the division of the leaves in C. roborowskii shows some variation, this feature, although conspicuous, does not preclude conspecificity of Chaetoseris potaninii, neither does the stated pappus feature. A closer inspection of the material is pending, but for the time being C. potaninii is included in Cicerbita roborowskii. As no discontinuity could be observed between plants having leaves with narrow (linear to linear-lanceolate or narrowly elliptic), ± entire lateral and terminal lobes on the one hand and those having leaves with wider (broadly lanceolate to ovate), 1- or 2-toothed lobes (originally described as Lactuca prattii) on the other hand, the inclusion of this latter species starting with Beauverd in 1910 is therefore maintained.