The Collaborative International Dictionary of English v.0.48:

goose-grass \goose-grass\ n. (Bot.),
   A low-growing perennial (Potentilla anserina) having leaves
   silvery beneath; foundin Northern U. S., Europe, and Asia.

   Syn: silverweed, goose-tansy, Potentilla anserina.
        [WordNet 1.5]