hemlock (n.)

poisonous plant native to Europe, transplanted to North America, Old English (Kentish) hemlic, earlier hymlice, hymblice, name of a poisonous plant; of unknown origin. Liberman suggests from root hem- "poison," perhaps with the plant name suffix -ling or -ig. As the name of the poison derived from the plant, c. 1600. The North American fir tree so called by 1670s in New England, from resemblance of the position and tenuity of its leaves to those of the plant.