Type:— CHINA. Sichuan: Jiulong County, Yangfanggou, in forest along the river, 2650 m, 14 October 2007, Y. S. Chen 7551 (holotype PE; isotype PE).

Herbs perennial, to 90 cm tall. Rhizomes ascending, unbranched, with many dark brown small roots. Stem solitary, erect, ca. 4 mm in diameter, nearly glabrous, winged, longitudinally striate, apically paniculately branched. Leaves petiolate, papery; lower leaf blade elliptic, 8–16(–20) cm long, 3.5–5.5(–7.2) cm wide, both surfaces green, glabrous, but with sparse short glandular hairs, margin undulate dentate to shallowly pinnatifid, mucronate, apex acute to acuminate, base slightly cordate, decurrent into stems forming wings. Petioles winged, 4–12 cm long, base wider, auriculate and semiamplexicaul; wings entire. Upper stem leaves narrowly elliptic to lanceolate, gradually smaller apically on stem, base attenuate, petioles much shorter. Capitula numerous, paniculate, in sparse corymbs at the end of branchlets or stems. Involucre campanulate, 4–5 mm in diameter. Phyllaries in ca. 5 rows, imbricate, margin entire, green to brown; outer phyllaries triangular-ovate, ca. 2 mm long, ca. 1 mm wide, leathery, pubescent, apex acute to obtuse; middle series of phyllaries longer, linear-oblong, pubescent, apex acute to acuminate; inner phyllaries linear-lanceolate, pubescent, apex acute to acuminate, 9.5–11 mm long, 1–1.2 mm wide. Receptacle flat, densely covered with persistent white bristles, bristles spine-like, 4–6 mm long. Florets 15–20, corolla purple, ca. 9.5 mm long, tubular-funnelform, glabrous, tube ca. 3.5 mm long, limb ca. 6 mm long, lobes ca. 3 mm long. Anthers ca. 8 mm long, apical appendage acute, basal appendages obtuse, auricles with lacerate tails ca. 1.8 mm long. Achenes cylindroid, ca. 2.5 mm long, ca. 0.8 mm wide, glabrous, ribbed. Pappus light brown; outer bristles scabrid, ca. 2 mm long; inner bristles 14–16, plumose, ca. 9 mm long.

Distribution and habitat:— Saussurea jiulongensis is currently known only from Jiulong County and Yanyuan County, southwestern Sichuan, China. It grows in forests or thickets at altitudes of 2650–3320 m.

Phenology:—Flowering and fruiting from August to October.

Etymology:—The specific epithet is derived from its type locality, Jiulong County. Chinese name: AżṈLẄ.

Additional specimens examined (paratypes):— CHINA. Sichuan: Yanyuan County, Wodi, Huolu Shan, in Pinus forests, 3320 m, 29 July 2011, Y. S. Chen & Y. C. Bi 11-073 (PE); Yanyuan County, Wodi, Huolu Shan, in thickets, 2900 m, 28 July 2011, Y. S. Chen & Y. C. Bi 11-063 (PE).

Discussion:— Saussurea jiulongensis belongs to S. subgen. Saussurea sect. Saussurea because of its well-developed stems, roots not fibrously split, leaves evenly arranged along the stem, capitula numerous and in sparse corymbs, anther tails lacerate. In our molecular tree, S. jiulongensis is shown to be closely related to S. pseudojiulongensis, S. pteridophylla Handel-Mazzetti (1936: 1149) and S. undulata Handel-Mazzetti (1936: 1147), these species share characters in winged petioles and leaves base decurrent along stem to form distinct wings, capitula shape, size and arrangement. It is different from S. pteridophylla by its leaf margin undulate-dentate to shallowly pinnatifid, mucronate (vs. pinnately lobed to pinnatisect, lateral lobes 6–10 pairs), petioles of lower leaves 4–12 cm long (vs. less than 2.5 cm long).