Sequoia sempervirens  (California Redwood) 

 

Sequoia sempervirens is the sole living species of the genus Sequoia in the cypress family Cupressaceae (formerly treated in Taxodiaceae).

 

Common names include coast redwood, coastal redwood and California redwood. It is an evergreen, long-lived, monoecious tree living 1,200–1,800 years or more. 

 

This species includes the tallest living trees on Earth, reaching up to 379 feet (115.5 m) in height (without the roots) and up to 29.2 feet (8.9 m) in diameter at breast height / dbh. 

 

These trees are also among the oldest living things on Earth. Before commercial logging and clearing began by the 1850s, this massive tree occurred naturally in an estimated 2,100,000 acres (8,500 km2) along much of coastal California (excluding southern California where rainfall is not sufficient) and the southwestern corner of coastal Oregon within the United States. An estimated 70% or more of ancient old-growth redwood trees have been displaced by environmental changes or cut down.

 

The coast redwood can reach 115 m (377 ft) tall with a trunk diameter of 9 m (30 ft). It has a conical crown, with horizontal to slightly drooping branches. The bark can be very thick, up to 1-foot (30 cm), and quite soft and fibrous, with a bright red-brown color when freshly exposed (hence the name redwood), weathering darker. The root system is composed of shallow, wide-spreading lateral roots.

 

Coast redwoods occupy a narrow strip of land approximately 750 km (470 mi) in length and 5–47 mi (8.0–75.6 km) in width along the Pacific coast of North America; the most southerly grove is in Monterey County, California, and the most northerly groves are in extreme southwestern Oregon.

 

The prevailing elevation range is 98–2,460 ft (30–750 m) above sea level, occasionally down to 0 and up to 3,000 ft (about 920 m).[14] They usually grow in the mountains where precipitation from the incoming moisture off the ocean is greater. The tallest and oldest trees are found in deep valleys and gullies, where year-round streams can flow, and fog drip is regular. The trees above the fog layer, above about 2,296 ft (700 m), are shorter and smaller due to the drier, windier, and colder conditions.

 

In addition, Douglas fir, pine, and tanoak often crowd out redwoods at these elevations. Few redwoods grow close to the ocean, due to intense salt spray, sand, and wind. Coalescence of coastal fog accounts for a considerable part of the trees' water needs.