Herbs, perennial, ca. 45 cm tall; rhizomes short, multibranched. Stems simple, bearing fascicled leaves and lateral stems at ends of branches, canaliculate, appressed shortly hairy, glabrate below, densely leafy. Leaves thin, lower leaves withered at anthesis, basal leaves (non-reproducing rosettes) petiolate, petiole longer than blade; blade lanceolate, 2-4 × ca. 1 cm, veins on both surfaces sparsely shortly hairy, base attenuate, apex acute or rounded, mucronate, margin sparsely serrate (teeth mucronulate); cauline leaves shortly winged petiolate, narrowly lanceolate, 3-8 × 0.4-0.8 cm, apex long acuminate. Capitula numerous in dense corymbiform synflorescences, ca. 10 cm in diam. Involucres broadly campanulate, ca. 1 cm in diam.; phyllaries 2-seriate, linear-lanceolate, 5-7 mm, densely hairy, apex acuminate; outer phyllaries shorter than inner ones, inner phyllaries glabrous below, margin scarious, apex reddish. Ray florets 2-seriate, blue (when dry), lamina oblanceolate, 4-5 × ca. 1 mm; disk florets 4-5 mm. Achenes (immature) obovoid, compressed, strigose, margin thick. Pappus white or brownish, equal, equaling disk corollas.

In aspect, Aster rockianus is similar to A. moupinensis, but its leaf shape and capitula are different. This species may be related to A. diplostephioides, but it differs in habit.

No specimens were seen by us.

● Yunnan (Tengchong).