(DC.) Benth. ex C.B.Clarke
Description
Aster diplostephioides is a striking alpine daisy of the high Himalaya and Tibetan borderlands, recorded by GBIF (322 occurrences) from China, India, Nepal and Bhutan. It inhabits open alpine meadows, grassy slopes, stony pastures and stream margins, typically between about 3000 and 4500 m. The plant illustrated was photographed in Bhutan's Haa (Haar) Valley at 4000 m in September, a high subalpine-to-alpine zone where short summers and intense insolation favour large-headed, single-flowered composites that bloom into the post-monsoon period.
It is a perennial herb arising from a stout, woody rhizome, producing erect, simple, glandular-hairy stems usually to 30-50 cm. The leaves are alternate, oblanceolate to spathulate, entire, somewhat clasping above, and clothed in spreading hairs. Each stem bears a single large, solitary capitulum subtended by herbaceous, often purple-tinged phyllaries in two or three rows. The numerous narrow ray florets are blue to violet-purple and conspicuously long, surrounding a central disc of yellow florets that turns orange-purple with age. The cypselae are flattened and hairy, bearing a pappus of unequal barbellate bristles.
The species was described as Heterochaeta diplostephioides by de Candolle and transferred to Aster by Bentham ex C.B. Clarke. Although molecular work has redistributed much of the former broad Aster, the high-elevation Himalayan asters such as this remain referable to Aster sensu stricto. Its conspicuous solitary heads make it a notable component of Himalayan alpine meadows. It is widespread within its montane range and not regarded as threatened, though alpine habitats face pressure from grazing intensification and climate warming.
Author: (DC.) Benth. ex C.B.Clarke · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Flowers of the Himalaya (Polunin & Stainton), Asteraceae of the Himalaya