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

hemlock \hem"lock\, n. oe. hemeluc, humloc, as. hemlic,
   hymlic.
   1. bot. the name of several poisonous umbelliferous herbs
      having finely cut leaves and small white flowers, as the
      cicuta maculata, cicuta bulbifera, and cicuta
      virosa, and the conium maculatum. see conium.
      1913 webster

   note: the potion of hemlock administered to socrates is by
         some thought to have been a decoction of cicuta
         virosa, or water hemlock, by others, of conium
         maculatum.
         1913 webster

   2. bot. an evergreen tree common in north america abies
      canadensis or tsuga canadensis; hemlock spruce.
      1913 webster

            the murmuring pines and the hemlocks. --longfellow.
      1913 webster

   3. the wood or timber of the hemlock tree.
      1913 webster

   ground hemlock, or dwarf hemlock. see under ground.
      1913 webster
see also:
cicuta maculata cicuta bulbifera cicuta virosa conium maculatum conium cicuta virosa 
conium maculatum abies canadensis tsuga canadensis ground hemlock dwarf hemlock 
ground 

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

water hemlock \wa"ter hem"lock\ bot
   a a poisonous umbelliferous plant cicuta virosa of
       europe; also, any one of several plants of that genus.
   b a poisonous plant oenanthe crocata resembling the
       above.
       1913 webster
see also:
cicuta virosa oenanthe crocata 

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

cowbane \cow"bane`\ kou"b=an`, n. bot.
   a poisonous umbelliferous plant; in england, the cicuta
   virosa; in the united states, the cicuta maculata and the
   archemora rigida. see water hemlock.
   1913 webster
see also:
cicuta virosa cicuta maculata archemora rigida water hemlock 

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