WordNet (r) 3.0 (2006):

Sequoiadendron giganteum
    n 1: extremely lofty evergreen of southern end of western
         foothills of Sierra Nevada in California; largest living
         organism [syn: giant sequoia, big tree, Sierra
         redwood, Sequoiadendron giganteum, Sequoia gigantea,
         Sequoia Wellingtonia]