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 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. 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 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.

Sabinaria magnifica is a species of palm tree and the only member of the genus Sabinaria. Native to the Darién Gap on the border between Colombia and Panama, it grows from 1 to 6 metres (3 ft 3 in to 19 ft 8 in) tall with large, deeply-divided leaf blades. It has been described as "striking", "spectacular" and "beautiful" by taxonomists.

Although known by local mule drivers, it was first collected in April 2013 by Saúl Hoyos, and described scientifically by Colombian palm experts Gloria Galeano and Rodrigo Bernal who named the genus Sabinaria after their daughter. Despite being locally abundant, the limited range occupied by the species makes it vulnerable to habitat destruction. (Full article...)

Did you know? - show different entries

Juvenile leaves of prickly ash

Selected article - show another

Sequoioideae, commonly referred to as Redwoods, is a subfamily of coniferous trees within the family Cupressaceae, that range in the northern hemisphere. It includes the largest and tallest trees in the world. The trees in the subfamily are amongst the most notable trees in the world and are common ornamental trees. In prehistoric times the genus Austrosequoia was common until the Oligocene. (Full article...)

General images

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

Selected lists


Category puzzle
Category puzzle
Select [►] to view subcategories

Related portals

Associated Wikimedia

The following Wikimedia Foundation sister projects provide more on this subject:

Discover Wikipedia using portals

Purge server cache