The Collaborative International Dictionary of English v.0.48:

Sequoia \Se*quoi"a\, n. [NL. So called by Dr. Endlicher in honor
   of Sequoyah, who invented the Cherokee alphabet.] (Bot.)
   A genus of coniferous trees, consisting of two species,
   Sequoia Washingtoniana, syn. Sequoia gigantea, the "big
   tree" of California, and Sequoia sempervirens, the redwood,
   both of which attain an immense height.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Redwood \Red"wood`\ (-w[oo^]d`), n. (Bot.)
   (a) A gigantic coniferous tree (Sequoia sempervirens) of
       California, and its light and durable reddish timber. See
       Sequoia.
   (b) An East Indian dyewood, obtained from Pterocarpus
       santalinus, Caesalpinia Sappan, and several other
       trees.
       [1913 Webster]

   Note: The redwood of Andaman is Pterocarpus dalbergioides;
         that of some parts of tropical America, several species
         of Erythoxylum; that of Brazil, the species of
         Humirium.
         [1913 Webster]

WordNet (r) 3.0 (2006):

Sequoia sempervirens
    n 1: lofty evergreen of United States coastal foothills from
         Oregon to Big Sur; it flourishes in wet, rainy, foggy
         habitats [syn: California redwood, coast redwood,
         Sequoia sempervirens]