D.Don.
Description
Pedicularis megalantha D.Don is a hemiparasitic perennial of the central and eastern Himalaya, with some 369 georeferenced GBIF occurrences from Pakistan, Nepal, northern India, Bhutan and adjacent southern Tibet (China). It favours moist subalpine and alpine meadows, open forest margins and damp streamsides, typically between about 2800 and 4200 m. The population photographed at Dur-Tso-Chu in Bhutan at 3400 m in June, beside a glacial-fed valley, is characteristic of the cool, humid summer habitats it favours, where it draws water and nutrients by haustorial attachment to the roots of neighbouring herbs and grasses.
The species forms erect, often unbranched stems 15-40 cm tall arising from a short rhizome and fascicled fleshy roots. The leaves are mostly cauline, oblong-lanceolate and pinnatisect, the lobes serrate to incised-dentate. The inflorescence is a loose terminal raceme of comparatively large, showy flowers; the calyx is tubular and cleft, and the corolla is pink to rose-purple with a strongly bent galea ending in a short slender beak that encloses the anthers, the lower lip broadly three-lobed. Pollination is by long-tongued bumblebees, and the fruit is an asymmetrical, beaked loculicidal capsule with several reticulate seeds.
Pedicularis is among the largest genera of Orobanchaceae and reaches its greatest diversity in the Sino-Himalayan region, where corolla architecture has radiated to match specialised bee pollinators. P. megalantha belongs to the large-flowered, shortly beaked alliance and is a conspicuous member of Himalayan meadow communities. As a root hemiparasite it influences surrounding vegetation and nutrient cycling. Though not assessed as threatened and locally frequent, its dependence on intact moist alpine turf makes it sensitive to overgrazing and to climate-driven shifts in the snow-melt regime.
Author: D.Don. · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, Robert R. Mill revision of Himalayan Pedicularis