Synonyms
Cicuta vagans Greene
Cicuta frondosa Greene
Cicuta occidentalis f. frondosa (Greene) Greene
Cicuta virosa var. californica (A.Gray) J.M.Coult. & Rose
Cicuta purpurata Greene
Cicuta sonnei Greene
Cicuta maculata var. californica (A.Gray) B.Boivin
Cicuta fimbriata Greene
Sium douglasii DC.