what is a tree?

In botany, a tree is a perennial woody plant with a single main trunk taller than about 2 metres, with xylem tissue in the trunk and branches that continues to enlarge during the life of the plant by the process of secondary growth.

In common usage, the definition of tree may be narrower, including only very tall plants or those that could yield significant wood. The definition can instead be broader, including tall plants without secondary growth such as the taller palms and the tree ferns. Bamboo is a tall woody plant that is not usually considered to be a tree.