lambkill

from WordNet (r) 3.0 (2006)

lambkill
    n 1: North American dwarf shrub resembling mountain laurel but
         having narrower leaves and small red flowers; poisonous to
         young stock [syn: {sheep laurel}, {pig laurel}, {lambkill},
         {Kalmia angustifolia}]

from The Collaborative International Dictionary of English v.0.48

Lambkill \Lamb"kill`\, n. (Bot.)
   A small American ericaceous shrub ({Kalmia angustifolia}),
   resembling mountain laurel but having narrower leaves and
   small red flowers; -- called also {calfkill}, {sheepkill},
   {sheep laurel}, etc. It is supposed to poison young sheep and
   other animals that eat it at times when the snow is deep and
   they cannot find other food.

   Syn: sheep laurel, pig laurel, {Kalmia angustifolia}.
        [Webster 1913 Suppl. + WordNet 1.5]