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.
Cicuta maculata L.
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 Cicutarootstocks:
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 bulbiferacontains too little toxin to be considered a threat.
Toxic plant chemicals:
Cicutol
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.
