Franch.
Description
Saussurea gossypiphora, the snowball or cotton-headed saussurea, is a remarkable high-alpine herb of the Himalaya and adjacent Tibetan China, recorded only from China and Nepal in GBIF with a mere 26 occurrences, reflecting both its extreme habitat and its restricted, fragmented distribution. It is among the highest-growing flowering plants, inhabiting open scree, moraine, gravelly alpine slopes and the margins of glacial debris in the upper alpine and subnival zone. The images document it in Sikkim near Samiti Lake at about 4400 m in August and in West Nepal on the Kagmara-La at around 4900 m in July, among the most extreme elevations at which it grows.
It is a stout, dwarf perennial herb forming a dense rosette, in which the upper leaves and the capitula are enveloped in a thick mass of long white woolly hairs forming a globose, cotton-wool-like dome. Beneath this insulating covering the leaves are oblanceolate, deeply toothed and arachnoid-hairy. The numerous small discoid capitula are clustered at the apex within the wool, each with purplish tubular florets and a multiseriate involucre. The fruit is a glabrous achene crowned by a feathery, plumose pappus aiding wind dispersal once the protective wool opens.
The dense lanate indumentum is a celebrated adaptation to the subnival environment, trapping heat, buffering night frost and ultraviolet radiation, and sheltering pollinating insects, paralleling the "glasshouse" and "woolly" growth forms found in other high-elevation Saussurea and Rheum. As a slow-growing, habitat-specialised plant of limited range it is potentially vulnerable to climate warming and collection pressure, though it has not been formally assessed.
Author: Franch. · Sources: POWO (Kew), GBIF, Flora of China, Flora of Nepal, Annotated Checklist of the Flowering Plants of Nepal, Lipschitz Monograph of the Genus Saussurea