Coast redwood, Sequoia sempervirens, is the sole living species of the genus Sequoia in the cypress family Cupressaceae. It is an evergreen, long-lived, monoecious tree living 1,200–1,800 years or more. The oldest known specimen is about 2,200 years old; many others in the wild exceed 600 years. This species includes the tallest trees on Earth, reaching up to 379 feet (115.52 m) in height and up to 26 feet (7.9 m) diameter at chest height. The current tallest tree has been named Hyperion, measuring in at 379.3 feet (115.6 m). The tree was discovered in Redwood National Park during the summer of 2006 by Chris Atkins and Michael Taylor, and has been measured as the world's tallest living organism.
Artist and horticulturist Morris Berd, whose Nature Study hangs in room 18 at the Barnes, gave a specimen of coast redwood to the Barnes Arboretum in 1971, as did Tom Dilatush in 1980; the surviving champion redwood is believed to be one of these.
Before commercial logging and clearing began in the 1850s, this massive tree occurred naturally in an estimated 2.1 million acres along much of coastal California (excluding southern California, where rainfall is not abundant enough) and the southwestern corner of coastal Oregon. The redwoods occupy a narrow strip of land approximately 450 miles (724 km) in length and 5 to 35 miles (8–56 km) in width.
An estimated 95% or more of the original old-growth redwood forest has been cut down for use in construction; coast redwood is one of the most valuable timber species in the lumbering industry. Redwood forests have the highest biomass of any terrestrial ecosystem in the world, more than 8 times the total aboveground biomass of a tropical rainforest. Because of its impressive resistance to decay, redwood was extensively used for railroad ties and trestles throughout California. Many of the old ties have been recycled for use in gardens as borders, steps, house beams, etc.
Redwood burls are used in the production of tabletops, veneers, and turned goods. Native Americans used redwood in the construction of canoes and as grave markers. Medicinally, it was used both to make hot poultices of the leaves to treat earache, and for its gummy sap, which was used as a stimulant and tonic in the treatment of rundown conditions. The bark can be used to make a brown dye. The sprouts from the burls have been used for basket weaving.
The coast redwood is locally naturalized in New Zealand, notably at Whakarewarewa Forest, Rotorua. Redwoods have been grown in New Zealand plantations for over 100 years, and they have higher growth rates than in California, mainly due to even rainfall distribution throughout the year.
The genus is widely thought to be named for Sequoyah, also known as George Guess, inventor and publisher of the Cherokee alphabet. The heartwood is red and is believed to be the origin of the name "redwood." In Latin, "sempervirens" means "evergreen" or "everlasting." Though the coast redwood and the giant sequoia (Sequoiadendron giganteum) are closest geographically, it is believed that the dawn redwood (Metasequoia glyptostroboides), found in China, is genetically closer. Redwood is the only naturally occurring hexaploid conifer. Redwoods (Sequoia sempervirens and Sequoiadendron giganteum) are the state tree of California.