Terran Common ash, a deciduous broad-leaved tree
Yggdrasil, the World Ash of Terran Norse mythology
In botany, a tree is a perennial plant with an elongated stem, or trunk, supporting branches and leaves in most species. Some definitions 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. Because of their longevity and usefulness, trees have always been revered and they play a role in many of Terra's mythologies.
Trees tend to be long-lived, some reaching several thousand years old. The tallest known Terran tree, a coast redwood named Hyperion, stands 115.6 m high. Trees have been in existence on Terra for 370 million years. 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.
A tree typically has secondary branches supported clear of the ground by the trunk. This trunk 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 ground, roots branch and spread out widely; they serve to anchor the tree and extract moisture and nutrients from the soil. Above ground, 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.
Union wide, all Type1, most Type 2A-C, Type 4A-B, and Type 6 Garden Worlds support some type of plant that is classified as a tree. (e.g. Green Hell Trappers Palm.)