The Collaborative International Dictionary of English v.0.48:

cow-cockle \cow-cockle\ n.
   a European annual (Vaccaria hispanica) with pale
   rose-colored flowers; cultivated flower or self-sown
   grainfield weed; introduced in North America; sometimes
   classified as a soapwort.

   Syn: cowherb, cow cockle, Vaccaria hispanica, Vaccaria
        pyramidata, Saponaria vaccaria.
        [WordNet 1.5]

The Collaborative International Dictionary of English v.0.48:

cowherb \cowherb\ n.
   a European annual with pale rose-colored flowers; cultivated
   flower or self-sown grainfield weed; introduced in North
   America; sometimes classified as a soapwort; -- also called
   the cow-cockle.

   Syn: cow cockle, cow-cockle, Vaccaria hispanica, Vaccaria
        pyramidata, Saponaria vaccaria.
        [WordNet 1.5]