Genus Cicuta
Parsley Family (Apiaceae/Umbelliferae)

Waterhemlock plant with flowers

(Cicuta douglasii

Waterhemlock is one of the most poisonous plants in North America.

All parts of the plant are very toxic. The poison affects the central nervous system, causing convulsions and death.

This is a native plant. It grows along streamsides, irrigation canals, and in moist pastures.


The tiny flowers grow in umbrella shaped clusters at the ends of the branches, later producing clusters of ridged oval seed pods.

The leaves are pinnately divided. The leaf veins end in the notches of the leaflet serrations, rather than at the tips.

Waterhemlock leaves