Sequoia, a genus of cone-bearing evergreen trees of the pine family. These trees were named after Sequoya, a Cherokee Indian leader and scholar. Sequoias are very tall, straight trees with furrowed reddish-brown bark. They surpass nearly all other plants in size and are among the oldest living things on earth. Sequoias were widely spread over the Northern Hemisphere before the Ice Age, which began about 2,000,000 years ago and continued to about 10,000 to 15,000 years ago. Fossil remains of sequoia trees have been found in many areas of Europe and the United States. Today the sequoia genus is represented by only two living species, found only in California and southwestern Oregon. These surviving sequoias are the redwood and the giant sequoia, which is also known as the big tree.
The redwood is a much taller tree than the giant sequoia. It grows to heights of about 275 to 350 feet (84 to 109 m), while the giant sequoia attains average heights of 250 to 280 feet (76 to 85 m). The giant sequoias, however, are much more massive and have longer life spans than the redwood. The oldest known giant sequoias are about 3,500 years old; the maximum life span of the redwoods is about 2,200 years. Both trees owe much of their remarkable life span to the facts that they are not easily destroyed by insects or disease and their bark is highly resistant to fire.
The giant sequoia grows in groves along the western slopes of the Sierra Nevadas at altitudes of about 4,500 to 8,000 feet (1,370 to 2,440 m). These trees grow at higher altitudes and in cooler areas than the redwoods. They have deep-green foliage and their leaves, which are small and scalelike, overlap one another. The woody oval cones are yellowish-brown and from two to three inches (5 to 7.5 cm) in length. The giant sequoia is not used as a timber tree; its wood is lightweight and brittle.
One of the most famous giant sequoia trees is the General Sherman tree in Sequoia National Park. Borings taken from the tree showed it to be about 3,500 years old. It is about 275 feet (84 m) tall and at ground level is 103 feet (31 m) in circumference. Some of the other national parks and national forests in which giant sequoia groves are preserved are Yosemite National Park, Kings Canyon National Park, and Sierra National Forest.
The redwood is the state tree of California. It requires a cool climate of high humidity, and is found only in the narrow fog belt along the Pacific coast from southern Oregon to Monterey, California.
Some of the tallest redwoods have been discovered in Redwood Creek Grove in Humboldt County, California. The tallest tree there measures about 370 feet (113 m) in height. Some areas have been established as state and national parks to preserve the largest and the most beautiful redwood groves. One of the most famous of these parks is Muir Woods National Monument.
Redwood trees have narrow, yellow-green leaves that are stiff, flat, and sharply pointed. The cones are egg-shaped and about one inch (2.5 cm) long. The redwoods are named for the reddish-brown lumber that is obtained from them. This lumber is very durable and is used for such things as shingles, fences, posts, and furniture. Redwood is heavier and stronger than the wood of the giant sequoia.
The redwood is Sequoia sempervirens; the giant sequoia, Sequoiadendron giganteum. The sequoia genus belongs to the pine family, Pinaceae. Some botanists classify the sequoia genus in the bald cypress family, Taxodiaceae.