Portal:Trees

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The Trees Portal

Common ash (Fraxinus excelsior), a deciduous broad-leaved (angiosperm) 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 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 parts 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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Ficus obliqua, commonly known as the small-leaved fig, is a tree in the family Moraceae, native to eastern Australia, New Guinea, eastern Indonesia to Sulawesi and islands in the southwestern Pacific Ocean. Previously known for many years as Ficus eugenioides, it is a banyan of the genus Ficus, which contains around 750 species worldwide in warm climates, including the edible fig (Ficus carica). Beginning life as a seedling, which grows on other plants (epiphyte) or on rocks (lithophyte), F. obliqua can grow to 60 m (200 ft) high and nearly as wide with a pale grey buttressed trunk, and glossy green leaves.

The small round yellow fruit ripen and turn red at any time of year, although ripening peaks in autumn and winter (April to July). Known as a syconium, the fruit is an inverted inflorescence with the flowers lining an internal cavity. Ficus obliqua is pollinated by two species of fig waspPleistodontes greenwoodi and P. xanthocephalus. Many species of bird, including pigeons, parrots and various passerines, eat the fruit. The range is along the east coast from Queensland, through New South Wales in rainforest, savanna woodland, sclerophyll forest and gallery forest. It is used as a shade tree in parks and public spaces, and is well-suited for use as an indoor plant or in bonsai. All parts of the tree have been used in traditional medicine in Fiji. (Full article...)

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Sabal bermudana

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Pomegranate (Punica granatum), Moyogi style, about 50 years old, at the Bonsai museum in Pescia, Italy.

Bonsai (Japanese: 盆栽, lit.'tray planting', pronounced [boɰ̃sai] (listen)) is the Japanese art of growing and training miniature trees in pots, developed from the traditional Chinese art form of penjing. Unlike penjing, which utilizes traditional techniques to produce entirely natural scenery in small pots that mimic the grandiose shapes of real life scenery, the Japanese "bonsai" only attempts to produce small trees that mimic the shape of real life trees. Similar versions of the art exist in other cultures, including the miniature living landscapes of Vietnamese Hòn non bộ. It was during the Tang dynasty, when penjing was at its height, that the art was first introduced in Japan.

The loanword "bonsai" (a Japanese pronunciation of the Chinese term penzai) has become an umbrella term in English, attached to many forms of diminutive potted plants, and also on occasion to other living and non-living things. According to Stephen Orr in The New York Times, "the term should be reserved for plants that are grown in shallow containers following the precise tenets of bonsai pruning and training, resulting in an artful miniature replica of a full-grown tree in nature." In the most restrictive sense, "bonsai" refers to miniaturized, container-grown trees adhering to Japanese tradition and principles. (Full article...)

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