Cicuta maculata is a rhizomatous perennial herb producing a hollow erect stem that can reach a height of 1.8 meters (6 feet).

Though a number of people have died from water hemlock poisoning over the centuries, livestock have long been the worst affected (hence the name "cowbane"), with ingestion of the plant causing death in as little as 15 minutes.

[12] Ingestion of water hemlock in any quantity can result in death or permanent damage to the central nervous system.

While the species as a whole is not under threat of extinction according to the International Union for Conservation of Nature[1] and NatureServe,[13] the variety C. maculata var.

[14] According to a 2022 Committee on the Status of Endangered Wildlife in Canada (COSEWIC) report, Victorin's water-hemlock, the sole variety of C. maculata that grows in parts of tidal marshes with brackish exposure and regular tidal inundation,[15]: 7  will soon qualify for threatened status if threats are not addressed.