Also found in: Thesaurus, Encyclopedia, Wikipedia.
Related to cowbane: water parsnip, water hemlock


1. A perennial North American herb (Oxypolis rigidior) in the parsley family, having pinnately compound leaves and umbels of small white flowers.
2. Any of several related plants, such as the water hemlock.


1. (Plants) Also called: water hemlock any of several N temperate poisonous umbelliferous marsh plants of the genus Cicuta, esp C. virosa, having clusters of small white flowers
2. (Plants) a similar and related plant, Oxypolis rigidior of the southeastern and central US
3. (Plants) any umbelliferous plant reputed to be poisonous to cattle



any of several poisonous plants of the parsley family, as Oxypolis rigidior, of swampy areas of North America, or the water hemlock, Cicuta maculata.
References in periodicals archive ?
Oxypolis rigidior (L.) Raf.; Cowbane, Stiff Cowbane, Common Water Dropwort; Wet roadside ditch and ditch fen; Infrequent; C = 7; BSUH 14774.
A few are very common species, while some are relatively uncommon [Amsonia tabernaemontana (blue star), Cicuta bulbifera (bulblet water hemlock), Oxypolis rigidior (cowbane), Ranunculus pensylvanicus (bristly crowfoot), Sparganium eurycarpum bur-reed)].
Other marsh plants such as marsh cinquefoil (Comarum palustre), cowbane (Cicuta virosa) and sedge (Carex) species were also observed.