Portal:Trees

Portal topics: Activities; Culture; Geography; Health; History; Mathematics; Nature; People; Philosophy; Religion; Society; Technology; Random portal

The Trees Portal

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 monophyletic taxonomic group but consist of a wide 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 around three trillion mature trees in the world.

A tree typically has many secondary branches supported clear of the ground by the trunk, which typically contains woody tissue for strength, and vascular tissue to carry materials from one part of the tree to another. For most trees it is surrounded by a layer of bark which serves as a protective barrier. Below the ground, the roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, the branches divide into smaller branches and shoots. The shoots typically bear leaves, which capture light energy and convert it into sugars by photosynthesis, providing the food for the tree's growth and development.

Trees usually reproduce using seeds. Flowers and fruit may be present, but some trees, such as conifers, instead have pollen cones and seed cones. Palms, bananas, and bamboos also produce seeds, but tree ferns produce spores instead.

Trees play a significant role in reducing erosion and moderating the climate. They remove carbon dioxide from the atmosphere and store large quantities of carbon in their tissues. Trees and forests provide a habitat for many species of animals and plants. Tropical rainforests are among the most biodiverse habitats in the world. Trees provide shade and shelter, timber for construction, fuel for cooking and heating, and fruit for food as well as having many other uses. In much of the world, forests are shrinking as trees are cleared to increase the amount of land available for agriculture. Because of their longevity and usefulness, trees have always been revered, with sacred groves in various cultures, and they play a role in many of the world's mythologies. (Full article...)

Refresh with new selections below (purge)

Recognized content - show another

Entries here consist of Good and Featured articles, which meet a core set of high editorial standards.

Ficus rubiginosa, the rusty fig or Port Jackson fig (damun in the Dharug language), is a species of flowering plant native to eastern Australia in the genus Ficus. Beginning as a seedling that grows on other plants (hemiepiphyte) or rocks (lithophyte), F. rubiginosa matures into a tree 30 m (100 ft) high and nearly as wide with a yellow-brown buttressed trunk. The leaves are oval and glossy green and measure from 4 to 19.3 cm (1+1⁄2–7+1⁄2 in) long and 1.25 to 13.2 cm (1⁄2–5+1⁄4 in) wide.

The fruits are small, round, and yellow, and can ripen and turn red at any time of year, peaking in spring and summer. Like all figs, the fruit is in the form of a syconium, an inverted inflorescence with the flowers lining an internal cavity. F. rubiginosa is exclusively pollinated by the fig wasp species Pleistodontes imperialis, which may comprise four cryptospecies. The syconia are also home to another fourteen species of wasp, some of which induce galls while others parasitise the pollinator wasps and at least two species of nematode. Many species of bird, including pigeons, parrots, and various passerines, eat the fruit. Ranging along the Australian east coast from Queensland to Bega in southern New South Wales (including the Port Jackson area, leading to its alternative name), F. rubiginosa grows in rainforest margins and rocky outcrops. It is used as a shade tree in parks and public spaces, and when potted is well-suited for use as an indoor plant or in bonsai. (Full article...)

List of recognized articles

Did you know? - show different entries

... that Gregory's tree (pictured), near Timber Creek in Australia's Northern Territory, bears inscriptions by 19th-century explorers and is registered as both a heritage place and an Aboriginal sacred site?
... that the Balderschwang Yew is possibly the oldest tree in Germany?
... that black truffles suppress plant growth around their host tree, creating an area that looks burned?
... that root extracts from the tree species Pycnanthus angolensis can be used to treat parasitic infections, such as schistosomiasis?
... that the lime trees of Duncliffe Wood are reputedly among the oldest living things in the county of Dorset?
... that trees of the New Guinea genus Finschia have stilt roots coming off the trunk up to 1.8 m (6 ft) off the ground?
... that in the early 1980s, a team of surveyors discovered the World War II-era Avro Anson Memorial near Clackline, Western Australia, which had been overgrown by shrubs and trees?

Start a new article

Selected article - show another

Krummholz (German: krumm, "crooked, bent, twisted" and Holz, "wood") — also called knieholz ("knee timber") — is a type of stunted, deformed vegetation encountered in the subarctic and subalpine tree line landscapes, shaped by continual exposure to fierce, freezing winds. Under these conditions, trees can only survive where they are sheltered by rock formations or snow cover. As the lower portion of these trees continues to grow, the coverage becomes extremely dense near the ground. In Newfoundland and Labrador, the formation is known as tuckamore. Krummholz trees are also found on beaches such as the Oregon coast, where trees can become much taller than their subalpine cousins.

The labeling of diverse sets of tree species in different ecological contexts may be problematic. The ecological requirements of krummholz trees in the Alps, for example, are different from those in the Rockies. The terms scrub or shrubland may be more appropriate for some communities with krummholz trees. (Full article...)

List of selected articles

General images

The following are images from various tree-related articles on Wikipedia.

Image 1Wind dispersed seed of elm (Ulmus), ash (Fraxinus) and maple (Acer) (from Tree)
Image 2Common ash (Fraxinus excelsior), a deciduous broad-leaved (angiosperm) tree (from Tree)
Image 3Dormant Magnolia bud (from Tree)
Image 4Conifers in the Swabian alps (from Tree)
Image 5Sugar maple (Acer saccharum) tapped to collect sap for maple syrup (from Tree)
Image 6Forest in the Scottish Highlands (from Forest)
Image 7Broadleaf forest in Bhutan (from Forest)
Image 8Since the 13th century, the Niepołomice Forest in Poland has had special use and protection. In this view from space, different coloration can indicate different functions. (from Forest)
Image 9European larch (Larix decidua), a coniferous tree which is also deciduous (from Tree)
Image 10Garibaldi Provincial Park, British Columbia (from Forest)
Image 11Yggdrasil, the World Ash of Norse mythology (from Tree)
Image 12The General Sherman Tree, thought to be the world's largest by volume (from Tree)
Image 13Latvian Pine Forest in Ķegums Municipality (from Forest)
Image 14People trees, by Pooktre (from Tree)
Image 15Buttress roots of the kapok tree (Ceiba pentandra) (from Tree)
Image 16Latex collecting from a rubber tree (Hevea brasiliensis) (from Tree)
Image 17The Daintree Rainforest (from Tree)
Image 18Palms and cycads as they might have appeared in the middle Tertiary (from Tree)
Image 19Even, dense old-growth stand of beech trees (Fagus sylvatica) prepared to be regenerated by their saplings in the understory, in the Brussels part of the Sonian Forest. (from Forest)
Image 20Spiny forest at Ifaty, Madagascar, featuring various Adansonia (baobab) species, Alluaudia procera (Madagascar ocotillo) and other vegetation (from Forest)
Image 214000 years old Cypress of Abarqu is the oldest tree in Iran and the second oldest tree in the world. (from List of trees of Iran)
Image 22Share of land that is covered by forest (from Forest)
Image 23A forest near Vinitsa, North Macedonia (from Forest)
Image 24Alnus glutinosa (from List of trees of Great Britain and Ireland)
Image 25Burned forest on Thasos (from Forest)
Image 26Priest River winding through Whitetail Butte with lots of forestry to the east—these lot patterns have existed since the mid-19th century. The white patches reflect areas with younger, smaller trees, where winter snow cover shows up brightly to the astronauts. Dark green-brown squares are parcels (from Forest)
Image 27World production of selected forest products (from Forest)
Image 28Informal upright style of bonsai on a juniper tree (from Tree)
Image 29Olive trees in Pakistan (from Trees of Pakistan)
Image 30Alleé of London plane trees (Platanus × acerifolia) in garden (from Tree)
Image 31The Amazon rainforest alongside the Solimões River, a tropical rainforest. These forests are the most biodiverse and productive ecosystems in the world. (from Forest)
Image 32Form, leaves and reproductive structures of queen sago (Cycas circinalis) (from Tree)
Image 33A young red pine (Pinus resinosa) with spread of roots visible, as a result of soil erosion (from Tree)
Image 34Roof trusses made from softwood (from Tree)
Image 35Malus sylvestris (from List of trees of Great Britain and Ireland)
Image 36Redwood tree in northern California redwood forest, where many redwood trees are managed for preservation and longevity, rather than being harvested for wood production (from Forest)
Image 37Proportion and distribution of global forest area by climatic domain, 2020 (from Forest)
Image 38Share of forest area in total land area, top countries (2021) (from Forest)
Image 39Selling firewood at a market (from Tree)
Image 40Proportion of forest in protected areas, by region, 2020 (from Forest)
Image 41Temperate rainforest in Tasmania's Hellyer Gorge (from Forest)
Image 42Northern beech (Fagus sylvatica) trunk in autumn (from Tree)
Image 43Tall herbaceous monocotyledonous plants such as banana lack secondary growth, but are trees under the broadest definition. (from Tree)
Image 44Diagram of secondary growth in a eudicot or coniferous tree showing idealised vertical and horizontal sections. A new layer of wood is added in each growing season, thickening the stem, existing branches and roots. (from Tree)
Image 45Lepidodendron, an extinct lycophyte tree (from Tree)
Image 46A section of yew (Taxus baccata) showing 27 annual growth rings, pale sapwood and dark heartwood (from Tree)
Image 47Trees in art: Weeping Willow, Claude Monet, 1918 (from Tree)
Image 48Neem tree at Sant Nenuram Ashram (from Trees of Pakistan)
Image 49Cracked thorny skin of a Aesculus tree seed (from Tree)
Image 50Recently stripped cork oak (Quercus suber) (from Tree)
Image 51Buds, leaves and reproductive structures of white fir (Abies alba) (from Tree)
Image 52Buds, leaves, flowers and fruit of oak (Quercus robur) (from Tree)
Image 53Fraxinus excelsior (from List of trees of Great Britain and Ireland)
Image 54Rowan tree in Wicklow, Ireland (from List of trees of Great Britain and Ireland)