Lindl.
Description
Trollius acaulis is a dwarf perennial of the high Himalaya, ranging along the alpine belt from Afghanistan and Pakistan through the western and central Himalaya into Nepal, Uttarakhand and Himachal Pradesh, and the western Tibetan Plateau in China. GBIF aggregates 188 georeferenced records, the species being strongest in the north-west. It grows in open alpine turf, moist grassy slopes, screes and snow-melt flushes, typically between 3000 and 4500 m. The plant photographed at Khiar Kutti in Garhwal at 3900 m in June is characteristic, flowering as the snow recedes.
It forms a compact, almost stemless herb arising from a short fibrous-rooted rhizome, the flowering stem reduced so the bloom appears to rest on the foliage (hence acaulis). The basal leaves are long-petiolate and palmately divided into deeply incised, toothed segments, glabrous and somewhat fleshy. The solitary flower is large, broadly cup-shaped and golden-yellow, the petaloid sepals enclosing numerous narrow nectariferous petals and a dense boss of stamens. The fruit is a head of many sessile, longitudinally veined follicles, each beaked and dehiscing ventrally to shed small angular seeds.
Within Ranunculaceae, Trollius (the globeflowers) is allied to Anemone and Ranunculus but set apart by its persistent petaloid sepals and clustered follicles. T. acaulis is among the most reduced, high-altitude members of the genus, its acaulescent habit an adaptation to short seasons, intense insolation and wind exposure. Like its congeners it yields acrid protoanemonin and is unpalatable to stock. Not assessed as threatened, it is nonetheless sensitive to overgrazing and the upward shift of climatic belts.
Author: Lindl. · Sources: POWO (Kew), GBIF, Flora of China Vol. 6, Flora of Pakistan, Flora of Bhutan Vol. 1, Annotated Checklist of the Flowering Plants of Nepal, Doroszewska monograph of the genus Trollius