The Collaborative International Dictionary of English v.0.48:

Erysimum \Erysimum\ n.
   a large genus of annual or perennial herbs of the Old World
   and North America; some are grown for their flowers and some
   for their attractive evergreen leaves.

   Syn: genus Erysimum.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Erysimum
    n 1: large genus of annual or perennial herbs some grown for
         their flowers and some for their attractive evergreen
         leaves; Old World and North America [syn: Erysimum,
         genus Erysimum]