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Oak
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") 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'' (stone oaks), as well as in those of unrelated species such as '' Grevillea robusta'' (silky oaks) 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 has the largest number of oak species, with approximately 160 species in Mexico of which 109 are endemic and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species. Description Oaks have spirally arranged leaves, with lobate margins in many species; some have serrated leaves or entire leaves with smooth margins. M ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quercus 20180406 100657
An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") 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'' (stone oaks), as well as in those of unrelated species such as ''Grevillea robusta'' (silky oaks) 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 has the largest number of oak species, with approximately 160 species in Mexico of which 109 are endemic and about 90 in the United States. The second greatest area of oak diversity is China, with approximately 100 species. Description Oaks have spirally arranged leaves, with lobate margins in many species; some have serrated leaves or entire leaves with smooth margins. Man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Quercus Species
The genus ''Quercus'' contains about 500 species, some of which are listed here. The genus, as is the case with many large genera, is divided into subgenera and sections. Traditionally, the genus ''Quercus'' was divided into the two subgenera ''Cyclobalanopsis'', the ring-cupped oaks, and ''Quercus'', which included all the other sections. However, a comprehensive revision in 2017 identified different relationships. Now the genus is commonly divided into a subgenus ''Quercus'' and a sugenus ''Cerris'', with ''Cyclobalanopsis'' included in the latter. The sections of subgenus ''Quercus'' are mostly native to the New World, with the notable exception of the white oaks of sect. ''Quercus'' and the endemic Quercus pontica. In contrast, the sections of the subgenus ''Cerris'' are exclusively native to the Old World. Legend Species with evergreen foliage (" live oaks") are tagged '#'. Species in the genus have been recategorized between deciduous and evergreen on numerous occasions, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedunculate Oak
''Quercus robur'', commonly known as common oak, pedunculate oak, European oak or English oak, is a species of flowering plant in the beech and oak family, Fagaceae. It is a large tree, native to most of Europe west of the Caucasus. It is widely cultivated in temperate regions elsewhere and has escaped into the wild in scattered parts of China and North America. Description ''Quercus robur'' is a large deciduous tree, with circumference of grand oaks from to an exceptional . The Majesty Oak with a circumference of is the thickest tree in Great Britain. The Brureika (Bridal Oak) in Norway with a circumference of (2018) and the Kaive Oak in Latvia with a circumference of are among the thickest trees in Northern Europe. The largest historical oak was known as the Imperial Oak from Bosnia and Herzegovina. This specimen was recorded at 17.5 m in circumference at breast height and estimated at over 150 m³ in total volume. It collapsed in 1998. The species has lobed and ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grevillea Robusta
''Grevillea robusta'', commonly known as the southern silky oak, silk oak or silky oak, silver oak or Australian silver oak, is a flowering plant in the family Proteaceae. It is a tree, the largest species in its genus but is not closely related to the true oaks, ''Quercus''. It is a native of eastern coastal Australia, growing in riverine, subtropical and dry rainforest environments. Description ''Grevillea robusta'' is a fast-growing evergreen tree with a single main trunk, growing to tall. The bark is dark grey and furrowed. Its leaves are fern-like, long, wide and divided with between 11 and 31 main lobes. Each lobe is sometimes further divided into as many as four, each one linear to narrow triangular in shape. It loses many of its leaves just before flowering. The flowers are arranged in one-sided, "toothbrush"-like groups, sometimes branched, long. The carpel (the female part) of each flower has a stalk long. The flowers are glabrous and mostly yellowish orange, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fagaceae
The Fagaceae are a family of flowering plants that includes beeches, chestnuts and oaks, and comprises eight genera with about 927 species. Fagaceae in temperate regions are mostly deciduous, whereas in the tropics, many species occur as evergreen trees and shrubs. They are 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 (usually containing one seed) 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lithocarpus
''Lithocarpus'' is a genus in the beech family, Fagaceae. Trees in this genus are commonly known as the stone oaks and differ from ''Quercus'' primarily because they produce insect-pollinated flowers on erect spikes and the female flowers have short styles with punctate stigmas. At current, around 340 species have been described, mostly restricted to Southeast Asia. Fossils show that ''Lithocarpus'' formerly had a wider distribution, being found in North America and Europe during the Eocene to Miocene epochs. The species extend from the foothills of the Hengduan Mountains, where they form dominant stands of trees, through Indochina and the Malayan Archipelago, crossing Wallace's Line and reaching Papua. In general, these trees are most dominant in the uplands (more than above sea level) and have many ecological similarities to the Dipterocarpaceae, the dominant lowland tree group. These trees are intolerant of seasonal droughts, not being found on the Lesser Sunda Island ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height. In wider definitions, the taller palms, tree ferns, bananas, and bamboos are also trees. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a trunk and branches as a way to tower above other plants to compete for sunlight. The majority of tree species are angiosperms or hardwoods; of the rest, many are gymnosperms or softwoods. Trees tend to be long-lived, some reaching several thousand years old. Trees have been in existence for 370 million years. It is estimated that there are some three trillion mature trees in the world. A tree typically has many secondary branches supported clear of the ground by the trunk. This trunk typicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marcescent
Marcescence is the withering and persistence of plant organs that normally are shed, and is a term most commonly applied to plant leaves. The underlying physiological mechanism is that trees transfer water and sap from the roots to the leaves through their vascular cells, but in some trees as autumn begins, the veins carrying the sap slowly close until a layer of cells called the abscission layer completely closes off the vein allowing the tree to rid itself of the leaf. Leaf marcescence is most often seen on juvenile plants and may disappear as the tree matures. It also may not affect the entire tree; sometimes leaves persist only on scattered branches. Marcescence is most obvious in deciduous trees that retain leaves through the winter. Trees that exhibit marcescence are known as "everciduous". Several trees normally have marcescent leaves such as oak (''Quercus''), beech (''Fagus'') and hornbeam (''Carpinus''), or marcescent stipules as in some but not all species of will ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Casuarinaceae
The Casuarinaceae are a family of dicotyledonous flowering plants placed in the order Fagales, consisting of four genera and 91 species of trees and shrubs native to eastern Africa, Australia, Southeast Asia, Malesia, Papuasia, and the Pacific Islands. At one time, all species were placed in the genus ''Casuarina''. Lawrence Alexander Sidney Johnson separated out many of those species and renamed them into the new genera of ''Gymnostoma'' in 1980 and 1982, ''Allocasuarina'' in 1982, and ''Ceuthostoma'' in 1988, with some additional formal descriptions of new species in each other genus. At the time, it was somewhat controversial. The monophyly of these genera was later supported in a 2003 genetics study of the family. In the Wettstein system, this family was the only one placed in the order Verticillatae. Likewise, in the Engler, Cronquist, and Kubitzki systems, the Casuarinaceae were the only family placed in the order Casuarinales. Members of this family are characterized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Evergreen
In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which completely lose their foliage during the winter or dry season. Evergreen species There are many different kinds of evergreen plants, both trees and shrubs. Evergreens include: *Most species of conifers (e.g., pine, hemlock, blue spruce, and red cedar), but not all (e.g., larch) *Live oak, holly, and "ancient" gymnosperms such as cycads *Most angiosperms from frost-free climates, and rainforest trees *All Eucalypts * Clubmosses and relatives * Bamboos The Latin binomial term , meaning "always green", refers to the evergreen nature of the plant, for instance :'' Cupressus sempervirens'' (a cypress) :''Lonicera sempervirens'' (a honeysuckle) :''Sequoia sempervirens'' (a sequoia) Leaf longevity in evergreen plants varies from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous
In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of ''deciduous'' in the botanical sense is evergreen. Generally, the term "deciduous" means "the dropping of a part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer, deciduous teeth (baby teeth) in some mammals (including humans); or decidua, the uterine lining that sheds off after birth. Botany In botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their leaves for part of the year. This process is called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nut (fruit)
A nut is a fruit consisting of a hard or tough nutshell protecting a kernel which is usually edible. In general usage and in a culinary sense, a wide variety of dry seeds are called nuts, but in a botanical context "nut" implies that the shell does not open to release the seed ( indehiscent). Most seeds come from fruits that naturally free themselves from the shell, but this is not the case in nuts such as hazelnuts, chestnuts, and acorns, which have hard shell walls and originate from a compound ovary. The general and original usage of the term is less restrictive, and many nuts (in the culinary sense), such as almonds, pecans, pistachios, walnuts, and Brazil nuts, are not nuts in a botanical sense. Common usage of the term often refers to any hard-walled, edible kernel as a nut. Nuts are an food energy, energy-dense and nutrient-rich food source. Botanical definition A seed is the mature fertilised ovule of a plant; it consists of three parts, the embryo which will d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
