More Articles . Trees are woody plants which continue growing until they die. They are perennial plants, and are classified as having a distinct, self-supporting main stem, or trunk, containing woody tissues that produces secondary limbs and branches. Their height and single main stem differentiate them from shrubs, which are usually shorter and have many stems.
Trees live anywhere from a few years to thousands of years.
There is a bristlecone pine growing in California's White Mountains that has been dated as at least 4700 years old. Trees grow just about everywhere on Earth , from extreme cold regions near the Arctic and the Antarctic to hot tropical regions around the equator and even in deserts. Although trees can grow singly, in nature they more often grow in stands consisting of one or of a mixture of species. As more trees toward the outside of the stand grow and become mature, they drop seeds and continue the spread of the stand. Forests are plant communities made up of the trees, shrubs, and many other plants and animals.