Royle
Description
Rheum moorcroftianum is a high-alpine rhubarb of the Western and Central Himalaya, ranging from Pakistan and Kashmir eastward through the Indian Himalaya (including Garhwal) and Nepal to the Tibetan plateau of China; GBIF records 129 occurrences across China, Nepal and India (with stray data points). It is a plant of open alpine slopes, screes, stabilised moraines, glacial flats and grazed meadows generally between 3500 and 5000 m, where it withstands intense insolation, drought and a short growing season. The illustrated specimen from Bagubasa in Garhwal at 4100 m in September shows the plant in its post-flowering, fruiting state at the close of the alpine summer.
It is a low, stout, often almost stemless perennial herb developing from a thick woody rhizome and tap-root. The conspicuous radical leaves form a flattened rosette and are orbicular to ovate-cordate, leathery, the blade prominently reticulate-veined and frequently flushed red or with reddish margins and undersides; petioles are short and stout. The inflorescence is a congested, scapose panicle scarcely exceeding the leaves, bearing numerous small flowers with usually six greenish to reddish perianth segments. The fruit is a broadly winged trigonous achene, the three membranous wings reddish-tinged and conspicuously veined, an adaptation aiding wind and surface dispersal across open terrain.
The species belongs to Rheum (Polygonaceae), a genus centred on the high mountains of Central Asia and the Sino-Himalaya. Its dwarf, ground-hugging rosette habit is a classic adaptation to the cold, windswept alpine environment, contrasting with the giant "glasshouse" rhubarbs such as R. nobile. Like other Himalayan Rheum it is locally harvested for medicinal roots and is subject to grazing pressure, but its wide range and remote habitat mean it is not currently considered threatened.
Author: Royle · Sources: POWO (Kew), GBIF, Flora of China Vol. 5, Flora of Pakistan, Flora of Nepal, A Revision of the Genus Rheum (Losina-Losinskaja)