Spotted water-hemlock-Cicuta maculata L.-Poisonous plant

Spotted water-hemlock

General poisoning notes:

Spotted water-hemlock (Cicuta maculata) is a native perennial herb found in wet soils and marshes across most of Canada and is considered the most violently toxic plant in North America. Humans and all classes of livestock are susceptible to poisoning and death after ingesting plant material. The onset of symptoms is often so sudden and traumatic that treatments are not always successful. The symptoms are similar in all cases of poisoning: salivation, muscular spasms, violent convulsions, coma, and death from asphyxiation. Death can occur within 15 minutes to 2-3 h after a lethal dose (Starrveld and Hope 1976, Panter et al. 1988).

Description

Cicuta maculata is a species of flowering plant in the carrot family known by several common names, including spotted water hemlock, spotted parsley, spotted cowbane, and the suicide root by the Iroquois. It is native to nearly all of North America, from northern Canada to southern Mexico. This is a rhizomatous perennial herb producing a hollow erect stem to a maximum height between 1 and 1.5 meters. The long leaves are made up of several lance-shaped, pointed, serrated leaflets. Each shiny green leaflet is 2 to 10 centimeters long and the entire leaf may be up to 40 centimeters long. The inflorescence of white flowers is similar in appearance to many other species in the carrot family. It is a compound umbel with a many clusters of flowers. The dry tan-brown fruit is a few millimeters long.

Nomenclature:

Scientific Name: Cicuta maculata L.

Vernacular name(s): spotted water-hemlock

Scientific family name: Umbelliferae

Vernacular family name: parsley

Geographic Information

Alberta, British Columbia, Manitoba, New Brunswick, Northwest Territories, Nova Scotia, Ontario, Prince Edward Island, Quebec, Saskatchewan.

Notes on Poisonous plant parts:

The toxin is concentrated in the rootstock in the spring. Later during the growing season, the roots contain less toxin, and the leaves and stems contain sufficient chemical to cause lethal poisoning (Starreveld and Hope 1975).

Toxic parts:

All parts, roots.

Notes on Toxic plant chemicals:

The chemical cicutoxin, (trans)heptadeca-8:10:12-triene-4:6-diene- 1:4-diol, is a highly unsaturated higher alcohol. Cicutol is also present. Bohlman (pers. comm.) in Mulligan and Munro (1981) found the following concentrations of these chemicals in Cicuta rootstocks:

Cicuta maculata var. maculata	1.01 mg/g active ingredients
Cicuta douglasii	0.75 mg/g
Cicuta virosa	0.07 mg/g
Cicuta bulbifera	0.01 mg/g

The first two Cicuta spp. are considered the most violently toxic plants in North America. Cicuta virosa is less likely to cause poisoning because of its reduced concentration of toxic compounds. Cicuta bulbifera contains too little toxin to be considered a threat.

Toxic plant chemicals:

Cicutol

Cicutoxin

Chemical diagram(s) are courtesy of Ruth McDiarmid, Biochemistry Technician, Kamloops Range Station, Agriculture and Agri-Food Canada, Kamploops, British Columbia, Canada.  

Animals/Human Poisoning:

Note: When an animal is listed without additional information, the literature (as of 1993) contained no detailed explanation.

Cattle

General symptoms of poisoning:

Convulsions, death, falling down, nervousness, salivation.

Notes on poisoning:

Cattle have symptoms of poisoning similar to those of other livestock. The symptoms include salivation, grinding of teeth, muscular spasms, violent convulsions, and death by asphyxiation. Smith and Lewis (1987) developed a rapid technique for identifying the presence of the toxic compounds of water-hemlocks in rumen samples.

Humans

General symptoms of poisoning:

abdominal pains

cardiac arrest

coma

confusion

convulsions

cyanosis

death

dizziness

eyeballs, protruding

eyes, rolling

faintness

heart rate, elevated

inebriation

metabolic acidosis

mouth, frothing of

muscle contractions

muscle spasms

muscle twitching

nausea

neck, rigid

opisthotonos

pupil dilation

pupils, pinpoint

reflex excitability

salivation

teeth grinding

unconsciousness

voiding, involuntary

vomiting.

Notes on poisoning:

Symptoms of poisoning by the genus Cicuta include dizziness, salivation, clenching and grinding of teeth, violent convulsions, cyanosis, coma, and death from asphyxiation. In one case, a fisherman took two bites from the roots and then felt dizzy and fell unconscious within 30 min. The patient endured pain and convulsions for some time. Recommended treatment includes administration of oxygen, anesthesia to control gross wild movements, and intravenous sodium bicarbonate to correct metabolic acidosis. At least 83 cases of human poisoning by water-hemlock have been reported since 1900, of which 21 were fatal. The rootstocks are generally distasteful, but ingesting of only one bite causes symptoms in humans (Starrveld and Hope 1976). These notes apply to all water-hemlock species (Cicuta) listed in this information system.

Sheep

General symptoms of poisoning:

Breathing, labored, death, recumbency.

Notes on poisoning:

Ewes weighing 70 kg were experimentally poisoned with fresh rootstock. The ewe given 100 g showed few symptoms; 200 g of plant material caused extensive symptoms including seizures, recumbency, and labored breathing. Recovery occurred after several days. Gavage with 450 g of the rootstock caused death in 90 min (Panter et al. 1988).

Swine

General symptoms of poisoning:

agonal squeals

brain, congestion of

convulsions

death

lesions, no specific

lungs, congestion of

muscle contractions

paralysis

reflex excitability.

Other info.

 This plant is one of the more toxic species of the Apiaceae or of any plant family for that matter. The plant has a pleasant licorice or anise scent when crushed but obviously it should not be eaten. It is easy to ID in the field because of its habitat, its glabrous and glaucous stems (which are purplish at the nodes), and its 2-3-pinnately divided leaves.