The Collaborative International Dictionary of English v.0.48:

Solidago \Sol`i*da"go\, n. [NL., fr. L. solidare to strengthen,
   unite; -- so called in allusion to its reputed healing
   qualities.] (Bot.)
   A genus of yellow-flowered composite perennial herbs;
   golden-rod.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Solidago
    n 1: goldenrod [syn: Solidago, genus Solidago]