The Collaborative International Dictionary of English v.0.48:

Helxine \Helxine\ n. (Bot.)
   A genus of plants consisting of one species; a dwarf creeping
   mat-forming evergreen herb.

   Syn: genus Helxine, Soleirolia, genus Soleirolia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Helxine
    n 1: one species; a dwarf creeping mat-forming evergreen herb
         [syn: Helxine, genus Helxine, Soleirolia, genus
         Soleirolia]