The Collaborative International Dictionary of English v.0.48:

Lysimachia \Lysimachia\ n.
   1. a cosmopolitan genus of plants, including some of the
      loosestrifes, found in damp or swampy terrain having
      usually yellow flowers; they are inclined to be invasive.

   Syn: genus Lysimachia.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

Lysimachia
    n 1: loosestrife: a cosmopolitan genus found in damp or swampy
         terrain having usually yellow flowers; inclined to be
         invasive [syn: Lysimachia, genus Lysimachia]