oak
An oak is a hardwood tree or shrub in the genus ''Quercus'' of the beech family. They have spirally arranged leaves, often with lobed edges, and a nut called an acorn, borne within a cup. The genus is widely distributed in the Northern Hemisp ...
. It is native to the Himalayas and nearby mountains in
Tibet
Tibet (; ''Böd''; ), or Greater Tibet, is a region in the western part of East Asia, covering much of the Tibetan Plateau and spanning about . It is the homeland of the Tibetan people. Also resident on the plateau are other ethnic groups s ...
, Afghanistan, India, Nepal, and Pakistan, where it is referred to as kharsu. It is classified in subgenus ''Cerris'', section ''Ilex''.
''Quercus semecarpifolia'' is an
evergreen
In botany, an evergreen is a plant which has Leaf, foliage that remains green and functional throughout the year. This contrasts with deciduous plants, which lose their foliage completely during the winter or dry season. Consisting of many diffe ...
Semecarpus anacardium
''Semecarpus anacardium'', commonly known as the marking nut tree, Malacca bean tree, marany nut, oriental cashew, dhobi nut tree and varnish tree, is a native of India, found in the outer Himalayas to the Coromandel Coast. It is closely related ...
.''
In its native range, it serves as a
keystone species
A keystone species is a species that has a disproportionately large effect on its natural environment relative to its abundance. The concept was introduced in 1969 by the zoologist Robert T. Paine. Keystone species play a critical role in main ...
, exhibiting up to 80% dominance at elevations between 2700 and 3300 meters. In areas where less degradation has occurred, ''Q. semecarpifolia'' reduces light at the forest floor, encouraging the growth of
shade tolerant
In ecology, shade tolerance is a plant's ability to tolerate low light levels. The term is also used in horticulture and landscaping, although in this context its use is sometimes imprecise, especially in labeling of plants for sale in nursery (ho ...
herbaceous
Herbaceous plants are vascular plants that have no persistent woody stems above ground. This broad category of plants includes many perennials, and nearly all annuals and biennials.
Definitions of "herb" and "herbaceous"
The fourth edition of ...
species. Local people make use of kharsu more frequently than other native oaks for food, animal fodder, fuel, and timber. Its leaves are also known to support '' Antheraea proylei'' silk worms, goats, and prevent slug infestations.
Fossil record
Fossils of ''Quercus semecarpifolia'' have been described from the
fossil flora of Kızılcahamam district
This fossil flora in Turkey stems from at least six Pliocene deposits in Güvem and Beşkonak villages, north of Ankara, north of Kızılcahamam and south of the Black Sea coast. They are to above sea level, extending north-south and eas ...
in
Turkey
Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...