Cicuta maculata L.

Stem Structure

Cicuta maculata is a rhizomatous perennial herb with a hollow, erect stem that can grow up to 1.8 meters (6 feet) tall.

Leaf Characteristics

Its long leaves are composed of multiple lance-shaped, pointed, serrated leaflets. Each shiny green leaflet measures 2 to 10 centimeters (1 to 4 inches) long, and the entire leaf may reach up to 40 centimeters (16 inches) in length.

Inflorescence Details

Its inflorescence of white flowers, which looks similar to the flower clusters of other species in the carrot family, is a compound umbel made up of many small flower clusters.

Fruit Traits

The plant produces dry tan-brown fruit that is only a few millimeters long.

Habitat and Flowering Period

This plant prefers wet habitats, including wet meadows, roadside ditches, pond margins, open marshes, and freshwater swamps, and it flowers from May to September.

Root Features and Misidentification

It has clusters of white tuberous roots, which leads it to be occasionally mistaken for parsnips.

Toxicity Status

This highly poisonous species is recognized as the most toxic native plant in North America.

Human Ingestion Effects

Any ingestion of Cicuta maculata is fatal, causing violent, painful convulsions.

Livestock Impacts

Over centuries, many people have died from water hemlock poisoning, but livestock have historically been the most impacted; this is why the plant is sometimes called cowbane, and ingestion can kill livestock in as little as 15 minutes.

Primary Toxic Compound

The primary toxic compound in Cicuta maculata is cicutoxin, an unsaturated aliphatic alcohol that is most concentrated in the plant's roots.

Acute Poisoning Symptoms

When consumed by humans, symptoms including nausea, vomiting, and tremors develop within 30 to 60 minutes, followed by severe cramps, projectile vomiting, and convulsions.

Long-Term Effects

Retrograde amnesia is a documented occasional long-term effect.

Severe Exposure Outcomes

Ingestion of any amount of this water hemlock can cause death or permanent damage to the central nervous system.