WordNet (r) 3.0 (2006):

American watercress
    n 1: mat-forming perennial found in cold springs of the eastern
         United States [syn: American watercress, mountain
         watercress, Cardamine rotundifolia]
    2: of southwestern Europe; cultivated in Florida [syn: Belle
       Isle cress, early winter cress, land cress, American
       cress, American watercress, Barbarea verna, Barbarea
       praecox]