Wall. ex Royle
Description
Parnassia nubicola Wall. ex Royle is a perennial herb of moist alpine habitats distributed along the Himalaya and into adjoining Central Asia, recorded from China, India, Nepal, Pakistan, Afghanistan and Bhutan, with around 182 georeferenced occurrences clustered in the high Sino-Himalayan ranges. It favours wet alpine meadows, marshy turf, seepage slopes, streamsides and the moist margins of snowmelt flushes, where soils remain saturated through the growing season. The photographed plants from Dzongri in Sikkim at about 4,200 m in August and from the Shele-La in Bhutan at about 4,000 m in September show its preference for the upper subalpine to alpine zone, where it flowers in late summer.
It grows from a short rhizome as a rosette of long-petioled basal leaves with ovate to cordate, entire blades. The flowering stems are erect and bear usually a single clasping, sessile cauline leaf below the solitary terminal flower. Each flower has five green sepals and five white petals conspicuously veined with green or yellowish lines. Between the fertile stamens lie five fringed staminodes divided into numerous gland-tipped filaments, a hallmark of the genus; the superior ovary ripens into a capsule splitting into four valves to release many small seeds.
The family attribution to Celastraceae follows recent molecular classifications, in which Parnassia (formerly placed in Saxifragaceae or its own Parnassiaceae) is treated within an expanded Celastraceae. The conspicuous nectar-secreting staminodes are associated with generalist insect pollination. Widespread and locally common across its broad range, P. nubicola is not considered threatened, though wetland alpine populations are sensitive to drainage, trampling and grazing.
Author: Wall. ex Royle · Sources: POWO (Kew), Flora of China Vol. 8, Flora of Bhutan Vol. 1, GBIF, Simmons: Celastraceae (in Kubitzki, 2004)