[1] : The Collaborative International Dictionary of English v.0.48

mouse-ear \mouse"-ear`\, n. bot.
      a the forget-me-not myosotis palustris and other
          species of the same genus.
      b a european species of hawkweed hieracium
          pilosella.
          1913 webster

   mouse-ear chickweed, a name of two common species of
      chickweed cerastium vulgarium, and cerastium
      viscosum.

   mouse-ear cress, a low cruciferous herb sisymbrium
      thaliana. all these are low herbs with soft, oval, or
      obovate leaves, whence the name.
      1913 webster
see also:
myosotis palustris hieracium pilosella mouse-ear chickweed cerastium vulgarium cerastium viscosum mouse-ear cress 
sisymbrium thaliana 

[2] : WordNet (r) 2.0

mouse-ear cress
     n : a small invasive self-pollinating weed with small white
         flowers; much studied by plant geneticists; the first
         higher plant whose complete genome sequence was described
         syn: arabidopsis thaliana
see also:
arabidopsis thaliana 

Cress >> C Words
Cress, definition of term: Cress
cress_pag1.html

Water Cress >> W Words
Water Cress, definition of term: Water Cress
water+cress_pag1.html