Album: Tree Photo (樹相片集) A tree is a large, perennial, woody plant. Though there is no set definition
regarding minimum size, the term generally applies to plants at least 6 m (20
ft) high at maturity and having secondary branches supported on a main stem or
stems (see shrub for comparison). Most trees exhibit clear apical dominance,
though this is not always the case (Mitchell, 1978). Compared with most other
plant forms, trees are long-lived. A few species of trees grow to 115 m (375 ft)
tall and some can live for several thousand years.