Giant Sequoia (Sequoiadendron giganteum); also Sierra redwood, Sierran redwood, or Wellingtonia; coniferous redwoods native only to groves on western slopes of Sierra Nevada Mountains. World's largest trees in terms of volume; grow to average height of 160–279 ft (50–85m) and 20-26 ft (6–8m) in diameter. Record trees 311 ft (94.8 m) tall and over 56 ft (17m) in diameter. Regenerate by seed only; require periodic fires to clear competing vegetation. Sequoia National Park, est. 9/25/1890; 404,051 acres (1,635 km2). Tulare County, CA.