H.L.Li
Description
Pedicularis megalochila is a high-alpine lousewort of the Eastern Himalaya, distributed across Bhutan, Sikkim and adjacent India, eastern Nepal and southern Tibet (Xizang) in China, with GBIF logging 62 occurrences over CN, BT, NP and IN. It inhabits open alpine turf, moist meadows, seepage slopes and the margins of glacial tarns at considerable altitude, typically between about 4000 and 4800 m. The photographed plant was recorded in Bhutan along the Ludlow-Sherriff Trail near Dem-Tso at 4650 m, flowering in June, consistent with the brief summer flowering window of high-elevation Pedicularis.
The species is a low perennial herb with a stout rootstock and short, ascending stems. The leaves are largely basal and rosulate, pinnatisect into closely set, toothed segments, with reduced cauline leaves. The flowers are aggregated into a dense terminal head or short spike, each subtended by a leafy bract. As the epithet megalochila implies, the zygomorphic corolla bears a notably large lower lip; the corolla is two-lipped, the upper lip forming a hooded, often beaked galea enclosing the four didynamous stamens, the colour ranging from rose-purple to pink. The calyx is tubular and toothed, and the fruit is an oblique, laterally compressed capsule containing few seeds.
Like all members of Pedicularis (now placed in Orobanchaceae), it is a hemiparasite, attaching by haustoria to the roots of neighbouring alpine plants while retaining green, photosynthetic foliage. The genus is exceptionally diverse and rapidly radiating in the Sino-Himalayan alpine zone, where bumblebee pollination and corolla architecture drive species differentiation. Its remote high-altitude habitat affords natural protection, and no specific conservation threat is currently documented.
Author: H.L.Li · Sources: POWO (Kew), GBIF, Flora of Bhutan, Flora of China (Scrophulariaceae/Orobanchaceae), H.L.Li and Tsoong revisions of Himalayan Pedicularis