Greene
Description
Bistorta vacciniifolia is a Sino-Himalayan alpine perennial distributed along the high mountain arc from Pakistan and northern India through Nepal, Sikkim and Bhutan into south-western China. The 525 GBIF records concentrate in this native range, with scattered occurrences in the Netherlands, Great Britain, New Zealand, Belgium, Norway and the United States representing rock-garden cultivation. It grows on open alpine slopes, rocky banks, moraines and the margins of dwarf-shrub heath, typically between about 3000 and 4500 m. The plant photographed below Dzongri in Sikkim at 4100 m in August captures it in flower during the late-monsoon alpine season on such stony, well-drained ground.
It is a low, mat- or cushion-forming herb arising from a stout, woody, often branched rhizome. The numerous slender, ascending stems bear small, leathery, ovate to elliptic leaves resembling those of Vaccinium, glabrous and shining above, paler beneath, with revolute margins, and sheathing membranous ochreae at the nodes. The inflorescence is a short, dense, terminal spike of bright rose-pink to deep red flowers, each with a five-lobed perianth, eight stamens and exserted styles. The fruit is a small, trigonous, dark brown nut enclosed by the persistent perianth.
Formerly placed in a broadly circumscribed Polygonum and still encountered under Persicaria, the species is now treated within Bistorta, the bistort knotweeds. Its cushion habit, woody rhizome and leathery evergreen leaves are adaptations to wind-exposed, frost-prone alpine ridges. Widespread and locally common across its range, it is of no conservation concern, though it remains an attractive component of high Himalayan moraine and heath communities.
Author: Greene · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Annotated Checklist of the Flowering Plants of Nepal