Thus, Yang and colleagues hypothesize that the inconsistent relationships among Metasequoia, Sequoia, and Sequoiadendron could be a sign of reticulate evolution (in which two species hybridize and give rise to a third) among the three genera. Further analysis strongly supported the hypothesis that Sequoia was the result of a hybridization event involving Metasequoia and Sequoiadendron. Using two different single copy nuclear genes, LFY and NLY, to generate phylogenetic trees, they found that Sequoia was clustered with Metasequoia in the tree generated using the LFY gene, but with Sequoiadendron in the tree generated with the NLY gene. However, Yang and colleagues in 2010 queried the polyploid state of the redwood and speculate that it may have arisen as an ancient hybrid between ancestors of the giant sequoia and dawn redwood ( Metasequoia). Molecular studies have shown that the three are each other's closest relatives, generally with the redwood and giant sequoia ( Sequoiadendron giganteum) as each other's closest relatives. The redwood is one of three living species, each in its own genus, in the subfamily Sequoioideae. Endlicher probably derived the name Sequoia from the Cherokee name of George Gist, usually spelled Sequoyah, who developed the still-used Cherokee syllabary. Austrian botanist Stephan Endlicher erected the genus Sequoia in his 1847 work Synopsis coniferarum, giving the redwood its current binomial name of Sequoia sempervirens. Scottish botanist David Don described the redwood as the evergreen taxodium ( Taxodium sempervirens) in his colleague Aylmer Bourke Lambert's 1824 work A description of the genus Pinus. Here, the term redwood on its own refers to the species covered in this article but not to the other two species. The name sequoia sometimes refers to the subfamily Sequoioideae, which includes S. sempervirens along with Sequoiadendron (giant sequoia) and Metasequoia (dawn redwood). Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated 810,000 hectares (2,000,000 acres) along much of coastal California (excluding southern California where rainfall is not sufficient) and the southwestern corner of coastal Oregon within the United States. These trees are also among the oldest living things on Earth. This species includes the tallest living trees on Earth, reaching up to 115.5 meters (379 ft) in height (without the roots) and up to 8.9 meters (29.2 ft) in diameter at breast height (dbh). It is an evergreen, long-lived, monoecious tree living 1,200–2,200 years or more. Common names include coast redwood, coastal redwood, and California redwood.
ə ˌ s ɛ m p ər ˈ v aɪ r ən z/) is the sole living species of the genus Sequoia in the cypress family Cupressaceae (formerly treated in Taxodiaceae).
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