Majumdar
Description
Arenaria edgeworthiana is a Himalayan sandwort recorded from Nepal, China, Bhutan and India, with around 96 georeferenced occurrences in GBIF. In the GBIF backbone the name is treated as a synonym; here Arenaria edgeworthiana is taken as the accepted name for the taxon. It occupies open, well-drained alpine habitats, including stony slopes, rock crevices, gravelly flats and short turf above the treeline, generally between roughly 3500 and 4500 m. The illustrated material was gathered at Shale-La in Bhutan at about 4100 m in September, a typical high-alpine station where this small mat-forming herb grows among scattered cushion plants on exposed ridges.
The plant is a low, tufted or cushion-forming perennial with slender, much-branched stems arising from a woody base. The leaves are small, opposite, sessile and narrowly linear to subulate, often somewhat rigid and crowded, giving the shoots a moss-like or imbricate appearance. The flowers are solitary or few in lax cymes, white, with five free sepals and five entire petals; the stamens are typically ten and the styles usually three, characters that place the plant securely within Arenaria sensu lato. The fruit is a small capsule dehiscing by valves and releasing several minute seeds.
The genus Arenaria has been repeatedly recircumscribed, with many Himalayan cushion species transferred among segregate genera such as Eremogone, which accounts for the synonymy reflected in databases. Plants of this group are well adapted to severe high-mountain conditions, their dense compact habit conserving heat and moisture. No formal conservation assessment applies, but like other restricted alpine endemics it depends on stable, undisturbed high-elevation habitat.
Author: Majumdar · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, McNeill revision of Arenaria