Hook. f. & Thomson
Description
Rheum acuminatum is a stout perennial wild rhubarb of the eastern and central Himalaya, distributed through China, Nepal, India, Bhutan and Myanmar, with some 370 documented records. It is a plant of subalpine and alpine slopes, rocky meadows, open shrubberies and stream margins, generally growing between 3000 and 4300 m. The illustrated plants come from Chele-La in Bhutan at 3900 m in July and the Lachung Valley in Sikkim at 3500 m in August, spanning the high-summer flowering and fruiting period characteristic of the species at these elevations.
The plant arises from a thick woody rhizome and produces erect, often reddish, hollow stems up to a metre or more tall. The basal leaves are large, long-petiolate and broadly ovate-cordate with an acuminate apex giving the epithet, the blade more or less glabrous above and with prominent venation; an ochrea sheaths the stem at each node. The inflorescence is a tall, branched panicle bearing numerous small flowers with a coloured perianth of six segments, white to greenish or reddish. The fruit is a broadly winged triangular achene (a three-angled, three-winged nutlet) adapted to wind and water dispersal.
The genus Rheum reaches its richest diversity in the Himalaya and the Qinghai-Tibetan plateau, where high-altitude rhubarbs show striking adaptations to cold, exposed habitats. R. acuminatum lacks the inflated bracts of the alpine glasshouse rhubarbs but shares the family's ochreate, trigonous-fruited architecture. The rhizomes have a history of local medicinal use, and although the species is widespread and not threatened, related wild rhubarbs are subject to harvesting pressure across the region.
Author: Hook. f. & Thomson · Sources: POWO (Kew), GBIF, Flora of China, Flora of Bhutan, Annotated Checklist of the Flowering Plants of Nepal, Losina-Losinskaja revision of Rheum