Aster mekongensis Onno, p.p.

Herbs, perennial, 8-25 cm tall; rhizomes robust, without stolons, collar clad with marcescent leaf remains. Stems ascending, simple, proximally villosulous, distally sparsely so, minutely stipitate glandular, more densely so distally. Leaves basal and cauline, thin, sparsely villosulous, more densely so on veins, moderately to densely minutely stipitate glandular, margin villous-ciliate, veins abaxially prominent, apices with purple mucro; basal leaves withered at anthesis, marcescent, broadly winged petiolate (petiole to 2 cm); blade oblanceolate, 0.9-2.5(-4.5) × 0.5-2.5 cm, base attenuate, margin serrulate (teeth mucronate), apex rounded to acute; lower cauline leaves oblong or obovate to oblanceolate, 1.5-4 × 0.5-1.2 cm, base rounded, subclasping, margin entire or dentate to serrulate; upper leaves approaching capitulum. Capitula terminal, solitary, 4-4.5 cm in diam. Involucres hemispheric, 11-13 × 13-14 mm, often overtopping disk; phyllaries 2- or 3-seriate, subequal, apex slightly spreading, oblong-lanceolate to lanceolate, 13-14 × 2.5-3.5 mm, abaxially sparsely villosulous to glabrate, tip densely minutely stipitate glandular, membranous, margin scarious, ciliate, multiveined, apex acuminate, ?leaflike, purplish. Ray florets 40-50(-70), blue-purple, lamina 12-15(-17) × 0.5-0.7 mm; disk florets purple-brown or yellow, ca. 5 mm, tube and proximal limb hairy, limb funnelform, ca. 4 mm, lobes erect, triangular, ca. 1 mm, tips sparsely minutely stipitate glandular. Achenes brown, narrowly obovoid, compressed, 2.5-3 mm, strigillose, minutely stipitate glandular, more densely so distally, 2-ribbed. Pappus 4-seriate, whitish to straw-colored; outermost series of few tiny scales 0.3-0.5 mm; bristles barbellate throughout; outer bristles slender, 2-3 mm; inner bristles 4-4.5 mm, acute; innermost bristles ca. 5 mm, weakly clavate. Fl. Jul-Aug, fr. Sep-Oct. 2n = 10.

Alpine meadows, Pinus forests; 3600-4800 m. Sichuan, S Xizang, NW Yunnan [Bhutan, India (Sikkim), N Myanmar, Nepal].