Water hemlock : A poisonous umbelliferous plant (Cicuta virosa) of Europe; also, any one of several plants of that genus.

Water hemlock : A poisonous plant (/nanthe crocata) resembling the above.

Example:


Taxonomy
water hemlock, Cicuta, plant, symptoms, cicutoxin, species, treatment, spp, PMID, family, water parsnip, Cicuta virosa, Cicuta maculata, common name, stem, family Apiaceae, poison hemlock, genus Conium.

Defination from the web:
water hemlock, plants in this genus may also be referred to as Cowbane or Poison Parsnip. ... Water Hemlock is unique in the Apiaceae family in that it has leaf veins which terminate in the notches between the leaf tips rather than extend ...