bottlegrass

from The Collaborative International Dictionary of English v.0.48

bottlegrass \bottlegrass\ n. (Bot.)
   a European foxtail naturalized in North America; it is often
   a troublesome weed.

   Syn: green bristlegrass, green foxtail, rough bristlegrass,
        bottle grass, Setaria viridis.
        [WordNet 1.5]