Sm.
Description
Quercus semecarpifolia, the kharsu oak, is an evergreen oak forming the highest-altitude oak forests of the Himalaya, native across China, Nepal, India, Bhutan, Pakistan and Afghanistan and extending into Myanmar and Thailand. It dominates upper montane and subalpine slopes, often at the treeline, generally between about 2400 and 3800 m, on cool, moist exposures. The trees photographed at Chele-La in Bhutan at 3000 m in May and along the Linji-Khola in West Nepal at 3300 m in June illustrate its role as the uppermost broad-leaved forest belt, frequently mixed with rhododendron, fir and birch near the limit of arborescent growth.
It is a large evergreen tree, gnarled and spreading at high elevations, with thick, fissured bark. The leaves are leathery and elliptic to oblong, dark glossy green above and golden- to rusty-tomentose beneath when young, the margin entire or with a few spiny teeth, especially on younger and coppice growth. It is monoecious, the male flowers in slender pendulous catkins and the female flowers solitary or few. The fruit is a large, hemispherical acorn seated in a shallow cup of appressed scales, maturing over a second season and providing important mast.
Quercus semecarpifolia belongs to subgenus Cerris (section Ilex, the ring-cupped oaks), the predominant oak lineage of the Sino-Himalayan mountains. As a treeline keystone it stabilises soils, supports rich epiphyte and understorey communities and yields hard timber, fuelwood and fodder, which makes it heavily exploited and in places poorly regenerating. Its acorns are dispersed by birds and rodents, and the species is regarded as ecologically critical yet locally threatened by overcutting and grazing across the Himalaya.
Author: Sm. · Sources: POWO (Kew), GBIF, Flora of China, Annotated Checklist of the Flowering Plants of Nepal, Flora of Bhutan, Menitsky's Oaks of Asia