Northern Water Hemlock
Cicuta virosa
Northern water hemlock is a perennial wetland plant primarily known for its extreme toxicity to humans and animals. It prefers nutrient-rich shores, ditches, and marshes across Eurasia and parts of North America. A distinctive feature is the bulbous, cross-chambered rhizome that exudes a yellowish sap when cut. The plant produces large, white compound umbels and has multi-pinnate leaves with serrated edges.
Details
Oxygen production
Minor oxygen release via the roots into the sediment (Radial Oxygen Loss).
Habitat function
Provides hiding places for aquatic insects and amphibians in the riparian zone.
Nutrient uptake
Absorbs nitrogen and phosphorus from the sediment and water.
Food source for
Food plant for hoverflies and specialized beetle species.
Human use
No modern use due to extreme toxicity (cicutoxin); historically used occasionally in homeopathy.
Ecology
Ecological role
Important component of reed bed communities; serves as a food source for specialized insects.
Natural predators
Specialized insect larvae (e.g., hemlock water-dropwort weevil) that are immune to the toxin.
Competitor species
Other tall herbs of the silting zone such as common reed (Phragmites australis) or cattails (Typha spp.).
Ecosystem service
Contributes to primary production and the structural complexity of riparian ecosystems.
Threats
Drainage of wetlands, excessive eutrophication, destruction of riparian buffer zones.
Scientific profile
Profile
Reproduction
Generative reproduction via nautochory (seeds float using air tissue). Vegetative reproduction through the detachment of rhizome fragments that can establish new colonies.
Protection & threats
Main threats
Drainage of wetlands, loss of natural shoreline structures, intensive ditch clearing, and excessive eutrophication.