An oak is a tree or shrub in the genus Quercus of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably Lithocarpus, as well as in those of unrelated species such as Grevillea robusta and the Casuarinaceae (she-oaks). The genus Quercus is native to the Northern Hemisphere, and includes deciduous and evergreen species extending from cool temperate to tropical latitudes in the Americas, Asia, Europe, and North Africa. North America contains the largest number of oak species, with approximately 90 occurring in the United States, while Mexico has 160 species of which 109 are endemic. The second greatest center of oak diversity is China, which contains approximately 100 species.
Quercus kelloggii, the California black oak, also known as Kellogg oak, is an oak in the red oak section, native to western North America. Although genetically separated from them for more than 20 million years its leaves are remarkably similar in appearance to several other members of the red oak section including the red oak and the black oak found in eastern and central North America.
Fagaceae is a family of flowering plants that includes beeches and oaks, and comprises eight genera with about 927 species. The Fagaceae are mostly deciduous but often evergreen trees and shrubs, characterized by alternate simple leaves with pinnate venation, unisexual flowers in the form of catkins, and fruit in the form of cup-like (cupule) nuts. Their leaves are often lobed and both petioles and stipules are generally present. Their fruits lack endosperm and lie in a scaly or spiny husk that may or may not enclose the entire nut, which may consist of one to seven seeds. In the oaks, genus Quercus, the fruit is a non-valved nut called an acorn. The husk of the acorn in most oaks only forms a cup in which the nut sits. Other members of the family have fully enclosed nuts. Fagaceae is one of the most ecologically important woody plant families in the Northern Hemisphere, as oaks form the backbone of temperate forest in North America, Europe, and Asia and one of the most significant sources of wildlife fodder.
Quercus petraea, commonly known as the sessile oak, Cornish oak, Irish Oak or durmast oak, is a species of oak tree native to most of Europe and into Anatolia and Iran. The sessile oak is the national tree of the Republic of Ireland, and an unofficial emblem in Wales and Cornwall.
The Dipterocarpaceae are a family of 16 genera and about 695 known species of mainly tropical lowland rainforest trees. The family name, from the type genus Dipterocarpus, is derived from Greek and refers to the two-winged fruit. The largest genera are Shorea, Hopea, Dipterocarpus, and Vatica. Many are large forest-emergent species, typically reaching heights of 40–70 m, some even over 80 m, with the tallest known living specimen 93.0 m tall. The species of this family are of major importance in the timber trade. Their distribution is pantropical, from northern South America to Africa, the Seychelles, India, Indochina, Indonesia, Malaysia and Philippines. The greatest diversity of Dipterocarpaceae occurs in Borneo. Some species are now endangered as a result of overcutting, extensive illegal logging, and habitat conversion. They provide valuable woods, aromatic essential oils, balsam, and resins, and are a source for plywood.
The acorn, or oaknut, is the nut of the oaks and their close relatives. It usually contains one seed, enclosed in a tough, leathery shell, and borne in a cup-shaped cupule. Acorns are 1–6 centimetres long and 0.8–4 cm on the fat side. Acorns take between 6 and 24 months to mature; see the list of Quercus species for details of oak classification, in which acorn morphology and phenology are important factors.
Shorea is a genus of about 196 species of mainly rainforest trees in the family Dipterocarpaceae. The genus is named after Sir John Shore, the governor-general of the British East India Company, 1793–1798. The timber of trees of the genus is sold under the common names lauan, luan, lawaan, meranti, seraya, balau, bangkirai, and Philippine mahogany.
Cratoxylum is a genus of flowering plants in the family Hypericaceae, native to tropical Asia. The generic name is from the Greek meaning "strong wood", referring to the timber.
Odoardo Beccari was an Italian naturalist who discovered the titan arum, the plant with the largest unbranched inflorescence in the world, in Sumatra in 1878. This botanist is denoted by the author abbreviation Becc. when citing a botanical name.
Dyera costulata, the jelutong, is a species of tree in the family Apocynaceae. It grows to approximately 60 metres (200 ft) tall with diameters of 2 metres, or even to 80 m (260 ft) tall with diameters to 3 m (10 ft), and boles clear and straight for 30 m (90 ft). It grows in Malaysia, Borneo, Sumatra and southern Thailand. Its natural distribution is scattered locales in low-elevation tropical evergreen forest.
Heliciopsis is a genus of about thirteen species of trees, constituting part of the flowering plant family Proteaceae. They grow naturally in Burma, Indo-China, SE. China, Thailand, Peninsular Malaysia, Borneo, Sumatra, Java (Indonesia) and the Philippines. The name means similar to the plant genus Helicia. Its closest relatives are Athertonia (Australia) and Virotia.
Dryobalanops beccarii, or Kapur Keladan, is a species of plant in the family Dipterocarpaceae. The species is named after Odoardo Beccari, 1843–1920, an Italian explorer and botanist. It is found in Peninsular Malaysia and Borneo. It is a large emergent tree, up to 65 m tall, found in mixed dipterocarp forests on shallow leached soils over both sandstone and shale. It is a heavy hardwood sold under the trade names of Kapur. It is recorded from at least four protected areas.
Dryobalanops fusca is a species of plant in the family Dipterocarpaceae. The species name fusca is derived from Latin and refers to the dark coloured indumentum This species is endemic to Borneo, where it is threatened due to habitat loss. It is a large emergent tree, up to 60 m tall, found in kerangas on raised beaches. It is a heavy hardwood sold under the trade names of Kapur.
Dryobalanops keithii is a species of plant in the family Dipterocarpaceae. The species is named after H.G. Keith, 1899–1982, a Conservator of Forests in North Borneo. This species is endemic to Borneo, where it is threatened due to habitat loss. It is a main canopy to low emergent tree, up to 40 m tall, found in mixed dipterocarp forest on well-drained but moist clay soils. It is a heavy hardwood sold under the trade names of Kapur.
Dryobalanops lanceolata is a species of plant in the family Dipterocarpaceae. The species name is derived from Latin and refers to the shape of the leaf. This species is endemic to Borneo. It is found in at least five protected areas, but is threatened elsewhere due to habitat loss.
Dryobalanops oblongifolia is a species of plant in the family Dipterocarpaceae, native to regions of Southeast Asia and Maritime Southeast Asia.
Dryobalanops rappa is a species of plant in the family Dipterocarpaceae. The species name is derived from Iban and refers to the species habitat. This species is endemic to Borneo. It is found in at least one protected areas, but is threatened elsewhere due to habitat loss.
Kapur is a dipterocarp hardwood from trees of the genus Dryobalanops found in lowland tropical rainforests of Malaysia, Indonesia and South-East Asia. It is a durable construction tropical timber. One variety, D. aromatica, is a source of camphor.
Crown shyness is a phenomenon observed in some tree species, in which the crowns of fully stocked trees do not touch each other, forming a canopy with channel-like gaps. The phenomenon is most prevalent among trees of the same species, but also occurs between trees of different species. There exist many hypotheses as to why crown shyness is an adaptive behavior, and research suggests that it might inhibit spread of leaf-eating insect larvae.
Lithocarpus coopertus is a tree in the beech family Fagaceae. The specific epithet coopertus is from the Latin meaning "covered over", referring to the acorn.
