Callitriche verna

from The Collaborative International Dictionary of English v.0.48

Starwort \Star"wort`\ (st[aum]r"w[^u]rt`), n. (Bot.)
   (a) Any plant of the genus {Aster}. See {Aster}.
   (b) A small plant of the genus {Stellaria}, having
       star-shaped flowers; star flower; chickweed. --Gray.
       [1913 Webster]

   {Water starwort}, an aquatic plant ({Callitriche verna})
      having some resemblance to chickweed.

   {Yellow starwort}, a plant of the genus {Inula}; elecampane.
      [1913 Webster]