Source : Webster's Revised Unabridged Dictionary (1913)

Tamarack \Tam"a*rack\, n. (Bot.)
   (a) The American larch; also, the larch of Oregon and British
       Columbia ({Larix occidentalis}). See {Hackmatack}, and
       {Larch}.
   (b) The black pine ({Pinus Murrayana}) of Alaska, California,
       etc. It is a small tree with fine-grained wood.

Source : WordNet®

Larix occidentalis
     n : tall larch of western North America have pale green sharply
         pointed leaves and oblong cones; an important timber tree
         [syn: {western larch}, {western tamarack}, {Oregon larch}]