The Collaborative International Dictionary of English v.0.48:

Houttuynia \Houttuynia\ n.
   A genus of plants having only one species; East Asian
   low-growing plant of wet places.

   Syn: genus Houttuynia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Houttuynia
    n 1: one species; east Asian low-growing plant of wet places
         [syn: Houttuynia, genus Houttuynia]