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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 evolved around 370 million years ago, and it is estimated that there are around three trillion mature trees in the world currently.

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 the trunk 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...)

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Banksia dentata, commonly known as the tropical banksia, is a species of tree in the family Proteaceae. It occurs across northern Australia, southern New Guinea and the Aru Islands. Growing as a gnarled tree to 7 m (23 ft) high, it has large green leaves up to 22 cm (8.7 in) long with dentate margins. The cylindrical yellow inflorescences, up to 13 cm (5.1 in) high, appear between November and May, attracting various species of honeyeaters, sunbirds, the sugar glider and a variety of insects. Flowers fall off the ageing spikes, which swell and develop follicles containing up to two viable seeds each.

Banksia dentata is one of four Banksia species collected by Sir Joseph Banks in 1770, and one of the four species published in 1782 as part of Carolus Linnaeus the Younger's original description of Banksia. Within the genus, it is classified in the series Salicinae, a group of species from Australia's eastern states. Genetic studies show it is a basal member within the group. Banksia dentata is found in tropical grassland known as savanna, and associated with Pandanus and Melaleuca. It regenerates from bushfire by regrowing from its woody base, known as a lignotuber. (Full article...)

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... 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?

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The "Grizzly Giant" in the Mariposa Grove, Yosemite National Park

Sequoiadendron giganteum, also known as the giant sequoia, giant redwood or Sierra redwood is a coniferous tree, classified in the family Cupressaceae in the subfamily Sequoioideae. Giant sequoia specimens are the most massive trees on Earth. They are native to the groves on the western slopes of the Sierra Nevada mountain range of California but are grown around the world.

The giant sequoia is listed as an endangered species by the IUCN with fewer than 80,000 remaining in its native California. The tree was introduced to the U.K in 1853 and now there are around 5,000 mature trees. (Full article...)

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General images

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

Image 1Northern beech (Fagus sylvatica) trunk in autumn (from Tree)
Image 2European larch (Larix decidua), a coniferous tree which is also deciduous (from Tree)
Image 3Burned forest on Thasos (from Forest)
Image 4Roof trusses made from softwood (from Tree)
Image 5Proportion of forest in protected areas, by region, 2020 (from Forest)
Image 6A forest near Vinitsa, North Macedonia (from Forest)
Image 7Since 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 8Redwood 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 9Yggdrasil, the World Ash of Norse mythology (from Tree)
Image 10Temperate rainforest in Tasmania's Hellyer Gorge (from Forest)
Image 11Palms and cycads as they might have appeared in the middle Tertiary (from Tree)
Image 12Alnus glutinosa (from List of trees of Great Britain and Ireland)
Image 13Share of land that is covered by forest (from Forest)
Image 14Common ash (Fraxinus excelsior), a deciduous broad-leaved (angiosperm) tree (from Tree)
Image 154000 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 16A young red pine (Pinus resinosa) with spread of roots visible, as a result of soil erosion (from Tree)
Image 17Malus sylvestris (from List of trees of Great Britain and Ireland)
Image 18Diagram 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 19Olive trees in Pakistan (from Trees of Pakistan)
Image 20Spiny forest at Ifaty, Madagascar, featuring various Adansonia (baobab) species, Alluaudia procera (Madagascar ocotillo) and other vegetation (from Forest)
Image 21Share of forest area in total land area, top countries (2021) (from Forest)
Image 22Forest in the Scottish Highlands (from Forest)
Image 23Neem tree at Sant Nenuram Ashram (from Trees of Pakistan)
Image 24Proportion and distribution of global forest area by climatic domain, 2020 (from Forest)
Image 25Wind dispersed seed of elm (Ulmus), ash (Fraxinus) and maple (Acer) (from Tree)
Image 26Recently stripped cork oak (Quercus suber) (from Tree)
Image 27World production of selected forest products (from Forest)
Image 28Buds, leaves and reproductive structures of white fir (Abies alba) (from Tree)
Image 29Cracked thorny skin of a Aesculus tree seed (from Tree)
Image 30Garibaldi Provincial Park, British Columbia (from Forest)
Image 31Latvian Pine Forest in Ķegums Municipality (from Forest)
Image 32A section of yew (Taxus baccata) showing 27 annual growth rings, pale sapwood and dark heartwood (from Tree)
Image 33Tall herbaceous monocotyledonous plants such as banana lack secondary growth, but are trees under the broadest definition. (from Tree)
Image 34Conifers in the Swabian alps (from Tree)
Image 35The General Sherman Tree, thought to be the world's largest by volume (from Tree)
Image 36Dormant Magnolia bud (from Tree)
Image 37The Daintree Rainforest (from Tree)
Image 38Selling firewood at a market (from Tree)
Image 39Trees in art: Weeping Willow, Claude Monet, 1918 (from Tree)
Image 40Lepidodendron, an extinct lycophyte tree (from Tree)
Image 41Sugar maple (Acer saccharum) tapped to collect sap for maple syrup (from Tree)
Image 42Even, 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 43Buds, leaves, flowers and fruit of oak (Quercus robur) (from Tree)
Image 44Broadleaf forest in Bhutan (from Forest)
Image 45Alleé of London plane trees (Platanus × acerifolia) in garden (from Tree)
Image 46The Amazon rainforest alongside the Solimões River, a tropical rainforest. These forests are the most biodiverse and productive ecosystems in the world. (from Forest)
Image 47Buttress roots of the kapok tree (Ceiba pentandra) (from Tree)
Image 48Informal upright style of bonsai on a juniper tree (from Tree)
Image 49Latex collecting from a rubber tree (Hevea brasiliensis) (from Tree)
Image 50Priest 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 51Form, leaves and reproductive structures of queen sago (Cycas circinalis) (from Tree)
Image 52Rowan tree in Wicklow, Ireland (from List of trees of Great Britain and Ireland)
Image 53People trees, by Pooktre (from Tree)
Image 54Fraxinus excelsior (from List of trees of Great Britain and Ireland)