- an endangered coniferous tree, Sequoiadendron giganteum (formerly Sequoia gigantea), of coastal California with massive girth and tremendous height, one of three extant species of subfamily Sequoioideae: the largest in volume and among the oldest of all living things, giant sequoias have been known to exceed 52,000 cubic feet (1,472 cubic meters) in trunk size, 300 feet (91.5 meters) in height, and 3,200 years in age.
