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Redwood, Coast — Sequoia is a genus in the cypress family Cupressaceae (formerly treated in Taxodiaceae), containing the single living species Sequoia sempervirens. Common names include Coast Redwood and California Redwood (it is one of three species of trees known as redwoods). It is an evergreen, long-lived, monoecious tree living for up to 2,200 years, and is the tallest tree in the world, reaching up to 115.5 m (379.1 ft) in height and 7 m (23 ft) diameter at the base. It is thought to be named after the Cherokee Indian leader, Sequoyah, though this is uncertain. Sequioa is also one of the only words in the English language with all vowels.
The name Sequoia is also used as a general term for the subfamily Sequoioideae in which this genus is classified together with Sequoiadendron (Giant Sequoia) and Metasequoia (Dawn Redwood).
The crown is conical, with horizontal to slightly drooping branches. The bark is very thick, up to 30 cm (12 in), and quite soft, fibrous with a bright red-brown when freshly exposed (hence the name ‘redwood’), weathering darker. The root system is composed of shallow, wide-spreading lateral roots. The leaves are variable, being 15-25 mm long and flat on young trees and shaded shoots in the lower crown of old trees, and scale-like, 5-10 mm long on shoots in full sun in the upper crown of older trees; there is a full range of transition between the two extremes. They are dark green above, and with two blue-white stomatal bands below. Leaf arrangement is spiral, but the larger shade leaves are twisted at the base to lie in a flat plane for maximum light capture. The seed cones are ovoid, 15-32 mm long, with 15-25 spirally arranged scales; pollination is in late winter with maturation about 8-9 months after. Each cone scale bears 3-7 seeds, each seed 3-4 mm long and 0.5 mm broad, with two wings 1 mm wide. The seeds are released when the cone scales dry out and open at maturity. The pollen cones are oval, 4-6 mm long. The species is monoecious, with pollen and seed cones on the same plant. Its genetic makeup is unusual among conifers, being a hexaploid (6n) and likely autoallopolyploid (AAAABB). The mitochondrial genome is (unlike other conifers) paternally inherited (Neale et al. 1989).
Coast Redwood is one of the most valuable timber species in California, with 364,000 ha of redwood forest, all second growth, managed for timber production. Coast Redwood lumber is highly valued for its beauty, light weight, and resistance to decay. It is also resistant to fire since it does not burn well due to its lack of resin.
