What is a tree? To tree or not to tree?
David
The definition {below} of the word tree varies among experts. Actually, the exact number of tree species worldwide is unknown. If we go with definition # 5, there are approximately 2,600. I f we go with definition # 1, there are at least 21,000 and if we go with definition #6, there would be 50,000 to as many as 100,000.
1 A woody plant growing on a single stem usually to a height of over two meters {approximately 6 foot 6 3/4 inches}.
2 A tall perennial woody plant having a main trunk and branches forming a distinct elevated crown; includes both gymnosperms {conifers} and angiosperms {flowering}.
3 A perennial woody plant having a main trunk and usually a distinct crown usually over 10 foot tall.
4 In arboricultural terminology, the definition of tree is a woody plant with one main trunk and a rather distinct and elevated head {crown}. If not altered through human intervention, true trees (such as elm trees) will, by definition, generally reach a height of 15 feet or more.
5 Any perennial woody plant of considerable size (usually over twenty feet high) and growing with a single trunk.
6 A woody perennial plant having a single usually elongate main stem generally with few or no branches on its lower part.
7 A woody plant at least 5 meters {16 foot 4 3/4 inches} high with a main stem the lower part of which is usually unbranched.
8 A very tall plant that is mostly wood, except for its leaves.
9 A tree is a woody plant with a single erect perennial trunk at least 3 inches in diameter at breast height {DBH). Most trees have definitely formed crowns of foliage and attain heights in excess of 13 feet.
10 A tree can be defined as a large, perennial woody plant.
