There are approximately 825 native and naturalized species of trees in the United States.

The oldest living tree is believed to be a California bristlecone pine tree named Methuselah, estimated to be 4700 years old.

The world's largest known living tree, the General Sherman giant sequoia in California, weighs as much as 41 blue whales or 740 elephants, about 6167 tons.

In about 1638, Galileo Galilei (1564-1643) suggested that trees could grow only to be about 300 feet tall because of factors involving form and materials.