North America has 35 species of native pine trees. Botanists categorize pine trees by the hardness of their wood, dividing the numerous species into the soft pines and the hard pines. The height and geographic location of the trees varies greatly among the various types of pines.
The pine tree family includes the pines as well as trees such as the Douglas fir, larches and hemlocks. The hard pines have needles that serve as leaves, with these needles typically growing in bundles of fives but sometimes fewer. Needles vary in size, with some as short as the 1-inch-long needles of the whitebark pine to as long as the 10-inch needles of slash pine. The cones of soft pines contain the seeds of the tree and are typically elongated. Most types of hard pines have needles in bundles of two or three and the cones are thicker and woody. All pines are evergreen and capable of living as long as 100 years. These trees do well in acidic soils and in full sun. Mature trees do not require much water.
At least one species of pine tree grows in every single state in the nation. The Eastern white pine has one of the largest geographical ranges of any pine in the United States, growing throughout the Northeast and into the Great Lakes states. The Ponderosa pine exists in large portions of the West, while much of Canada is home to jack pine and lodgepole pine. Jeffrey, knobcone and Coulter pine trees are examples of pines with a very limited range; all three grow in the far Western states.
Sugar pine is the tallest of all the pine trees in America, with some springing up to heights of 180 feet. Other tall pine species include the Ponderosa pine, which can grow to 180 feet, and the Western white pine, which can exceed 175 feet. Medium-range pines are the Eastern white pine and the red pine, both of which may be 100 feet tall. Among the shortest pines in the country are the foxtail, pinyon and bristlecone pines, all of which seldom get bigger than 50 feet and often are only 20 feet tall.
The bark of pine trees not only differs among species, it frequently changes on the individual tree itself as the pine grows older. The Eastern white pine has smooth gray bark when it is young, but this bark turns into a series of rectangle-shaped blocks as the tree ages. Species such as jack pine and lodgepole pine have a rough scaly bark. The bark of Jeffrey pine turns into what looks like elongated plates.
Pine is a major source of wood for the lumber industry and wood pulp for the paper industry. Birds and many different kinds of animals such as squirrels will eat the seeds of a pine tree. Pine trees are popular as ornamental trees, and landscapers also plant them as windbreaks or to provide privacy. Pine boughs are a favorite of decorators at Christmas with their fragrant scent.