The Collaborative International Dictionary of English v.0.48:

Water speedwell \Wa"ter speed"well\ (Bot.)
   A kind of speedwell (Veronica Anagallis) found in wet
   places in Europe and America.
   [1913 Webster]

WordNet (r) 3.0 (2006):

water speedwell
    n 1: plant of wet places in Eurasia and America [syn: water
         speedwell, Veronica michauxii, Veronica anagallis-
         aquatica]