Tree
/triː/
Definition
Tree refers to a long-lived woody plant form, usually with one main trunk and a raised crown of branches and leaves. Unlike shrubs, it is typically taller and has a more distinct trunk, though the boundary is not exact. Most trees enlarge through secondary growth, meaning the stem thickens each year as wood and bark form. Trees occur in many plant groups, including both broadleaf species and conifers.
Botanical Significance
- Woody longevity: A tree typically invests in secondary growth, the thickening produced by tissues called cambium. This allows long-term support, water transport, and storage over many growing seasons.
- Canopy and competition: Its tall form positions leaves above many neighboring plants, increasing access to light. The resulting canopy also changes shade, temperature, and moisture conditions below it.
- Habitat for reproduction: Flowers, cones, fruits, and seeds are often displayed across a large branching framework. That structure can improve exposure to wind or animal pollinators and expand seed dispersal range.
- Useful identification trait: Growth form is an important clue in plant identification and classification, though it is not enough on its own. Some related species differ mainly in whether they develop as a tree or as a shrub under certain conditions.
Related Terms
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