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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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Alnus glutinosa, the common alder, black alder, European alder, European black alder, or just alder, is a species of tree in the family Betulaceae, native to most of Europe, southwest Asia and northern Africa. It thrives in wet locations where its association with the bacterium Frankia alni enables it to grow in poor quality soils. It is a medium-sized, short-lived tree growing to a height of up to 30 metres (98 feet). It has short-stalked rounded leaves and separate male and female flowers in the form of catkins. The small, rounded fruits are cone-like and the seeds are dispersed by wind and water.

The common alder provides food and shelter for wildlife, with a number of insects, lichens and fungi being completely dependent on the tree. It is a pioneer species, colonising vacant land and forming mixed forests as other trees appear in its wake. Eventually common alder dies out of woodlands because the seedlings need more light than is available on the forest floor. Its more usual habitat is forest edges, swamps and riverside corridors. The timber has been used in underwater foundations and for manufacture of paper and fibreboard, for smoking foods, for joinery, turnery and carving. Products of the tree have been used in ethnobotany, providing folk remedies for various ailments, and research has shown that extracts of the seeds are active against pathogenic bacteria. (Full article...)

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... that fossil leaves almost identical to those of the Australian rainforest tree Orites excelsus (pictured) have been found in New Zealand?
... that more than 8000 trees were planted in Backmuir Wood to celebrate the 2000 millennium?
... that the name of the newly defined genus of macadamia-like trees, Lasjia, is derived from the initials of Lawrence Alexander Sidney Johnson?
... that at St Athan, a wild fig tree grew out of the cement of the East Orchard chapel walls?
... that in the churchyard of St Mary and St Peter's Church in Wilmington, East Sussex, there is a 1,600-year-old, 23-foot (7 m) wide yew tree?
... that Christopher Werner made a lifelike South Carolina Palmetto tree out of iron, copper, and brass?
... that seed from an endangered Chrysophyllum imperiale tree planted in Royal Botanic Gardens, Sydney in 1868 by Prince Alfred has been sent to its native Brazil to aid in recovering the species there?

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Axel Erlandson (December 15, 1884 – April 28, 1964) was a Swedish American farmer who shaped trees as a hobby, and opened a horticultural attraction in 1947 called "The Tree Circus", advertised with the slogan "See the World's Strangest Trees Here".

The trees appeared in the column of Robert Ripley's Believe It or Not! twelve times. Erlandson sold his attraction shortly before his death. The trees were moved to Gilroy Gardens in 1985. (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 2Lepidodendron, an extinct lycophyte tree (from Tree)
Image 3Malus sylvestris (from List of trees of Great Britain and Ireland)
Image 4Latvian Pine Forest in Ķegums Municipality (from Forest)
Image 5Neem tree at Sant Nenuram Ashram (from Trees of Pakistan)
Image 6Conifers in the Swabian alps (from Tree)
Image 7A forest near Vinitsa, North Macedonia (from Forest)
Image 8Yggdrasil, the World Ash of Norse mythology (from Tree)
Image 9Priest 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 10Wind dispersed seed of elm (Ulmus), ash (Fraxinus) and maple (Acer) (from Tree)
Image 11Buds, leaves, flowers and fruit of oak (Quercus robur) (from Tree)
Image 12A young red pine (Pinus resinosa) with spread of roots visible, as a result of soil erosion (from Tree)
Image 13The Daintree Rainforest (from Tree)
Image 14Redwood 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 15World production of selected forest products (from Forest)
Image 16Latex collecting from a rubber tree (Hevea brasiliensis) (from Tree)
Image 17Cracked thorny skin of a Aesculus tree seed (from Tree)
Image 18A section of yew (Taxus baccata) showing 27 annual growth rings, pale sapwood and dark heartwood (from Tree)
Image 19Share of land that is covered by forest (from Forest)
Image 20Proportion of forest in protected areas, by region, 2020 (from Forest)
Image 21Roof trusses made from softwood (from Tree)
Image 22Dormant Magnolia bud (from Tree)
Image 23Alnus glutinosa (from List of trees of Great Britain and Ireland)
Image 24Common ash (Fraxinus excelsior), a deciduous broad-leaved (angiosperm) tree (from Tree)
Image 25Selling firewood at a market (from Tree)
Image 26Share of forest area in total land area, top countries (2021) (from Forest)
Image 27European larch (Larix decidua), a coniferous tree which is also deciduous (from Tree)
Image 28The General Sherman Tree, thought to be the world's largest by volume (from Tree)
Image 29Garibaldi Provincial Park, British Columbia (from Forest)
Image 30Proportion and distribution of global forest area by climatic domain, 2020 (from Forest)
Image 31Diagram 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 32Tall herbaceous monocotyledonous plants such as banana lack secondary growth, but are trees under the broadest definition. (from Tree)
Image 33Broadleaf forest in Bhutan (from Forest)
Image 34Trees in art: Weeping Willow, Claude Monet, 1918 (from Tree)
Image 35Buds, leaves and reproductive structures of white fir (Abies alba) (from Tree)
Image 36Buttress roots of the kapok tree (Ceiba pentandra) (from Tree)
Image 37Since 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 38Rowan tree in Wicklow, Ireland (from List of trees of Great Britain and Ireland)
Image 39Recently stripped cork oak (Quercus suber) (from Tree)
Image 40Spiny forest at Ifaty, Madagascar, featuring various Adansonia (baobab) species, Alluaudia procera (Madagascar ocotillo) and other vegetation (from Forest)
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 43Alleé of London plane trees (Platanus × acerifolia) in garden (from Tree)
Image 44Informal upright style of bonsai on a juniper tree (from Tree)
Image 45Olive trees in Pakistan (from Trees of Pakistan)
Image 46Temperate rainforest in Tasmania's Hellyer Gorge (from Forest)
Image 474000 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 48Palms and cycads as they might have appeared in the middle Tertiary (from Tree)
Image 49Form, leaves and reproductive structures of queen sago (Cycas circinalis) (from Tree)
Image 50Burned forest on Thasos (from Forest)
Image 51People trees, by Pooktre (from Tree)
Image 52The Amazon rainforest alongside the Solimões River, a tropical rainforest. These forests are the most biodiverse and productive ecosystems in the world. (from Forest)
Image 53Forest in the Scottish Highlands (from Forest)
Image 54Fraxinus excelsior (from List of trees of Great Britain and Ireland)