Tree

In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. 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. Trees are not a taxonomic group but include a variety of plant species that have independently evolved a woody trunk and branches as a way to tower above other plants to compete for sunlight. In looser senses, the taller palms, the tree ferns, bananas and bamboos are also trees. Trees tend to be long-lived, some reaching several thousand years old. The tallest known tree, a coast redwood named Hyperion, stands 115.6 m (379 ft) high. Trees have been in existence for 370 million years. It is estimated that there are just over 3 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. Flowers and fruit may also be present, but some trees, such as conifers, instead have pollen cones and seed cones; others, such as tree ferns, produce spores instead.

Melia azedarach

Melia azedarach, commonly known by many names, including white cedar,chinaberry tree,bead-tree, Cape lilac,syringa berrytree,Persian lilac, and Indian lilac, is a species of deciduous tree in the mahogany family, Meliaceae, that is native to Indomalaya and Australasia.

Description

The adult tree has a rounded crown, and commonly measures 7–12 metres (20–40 ft) tall, however in exceptional circumstances M. azedarach can attain a height of 45 metres (150 ft).

The leaves are up to 50 centimetres (20 in) long, alternate, long-petioled, two or three times compound (odd-pinnate); the leaflets are dark green above and lighter green below, with serrate margins.

The flowers are small and fragrant, with five pale purple or lilac petals, growing in clusters.

The fruit is a drupe, marble-sized, light yellow at maturity, hanging on the tree all winter, and gradually becoming wrinkled and almost white.

Nomenclature

Melia azedarach should not be confused with the Azadirachta trees, which are in the same family, but a different genus.