Western water-hemlock
General poisoning notes:
Western water-hemlock (Cicuta douglasii) is a native perennial plant found in wet soils in British Columbia. This plant is poisonous to all types of livestock and to humans. Many cases of poisoning have occurred in cattle, sheep, and horses. Pigs seem more resistant to the toxins, but they have still been poisoned. Humans have also been poisoned by this plant. Children are especially susceptible because ingestion of only one bite of the rootstock is sufficient to cause death. The onset of symptoms is so rapid that treatment may not be successful (Starrveld and Hope 1975, James and Ralphs 1986). See additional information in the general notes under Cicuta maculata.
Description:
The characteristics of water hemlock include its stem which is 0.5–2 meters tall with purplish spots, thick roots, and leaves that are compound pinnate and alternate. The leaflets are usually 5–8 cm long and 1–2 cm wide with jagged edges. The flowers on it are compound umbellate inflorescences with many small, white flowers. There are two seeds for each flower. Seed dispersal for water hemlock seeds comes from means of wind, water, machinery, on clothing, and through transported soil. The seeds germinate in spring, and flowers mature near the end of June and beginning of July. In addition to sprouting new plants from seeds, rootstocks can also product new plants. These are formed in the fall from the basal meristem, and when they detach the following spring, they may form a new plant.
Cicuta douglasii (DC.) Coult. & Rose
Nomenclature:
Scientific Name: Cicuta douglasii (DC.) Coult. & Rose
Vernacular name(s): western water-hemlock
Scientific family name: Apiaceae
Vernacular family name: parsley
Geographic Information:
British Columbia.
Notes on Poisonous plant parts:
The toxins are concentrated in the chambered rootstock but also occur in the leaves and stems as well (James and Ralphs 1986).
Toxic parts:
Leaves, roots, young shoots.
Notes on Toxic plant chemicals:
Cicutoxin is a highly unsaturated alcohol that is very toxic. The following dosages have been found:
Lethal dose (fresh green plant material) | Animal |
0.1 kg | sheep |
0.4 kg | cattle |
0.3 kg | horse |
Pigs appear to be more resistant to poisoning than other livestock. Adult humans can be poisoned and can die with only two or three bites of the rootstock (Starrveld and Hope 1975, James and Ralphs 1986).
Toxic plant chemicals:
Cicutoxin.
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:
Bloat, coma, convulsions, death by asphyxiation, lesions, no specific, muscle spasms, muscle twitching, nervousness, salivation.
Notes on poisoning:
Symptoms of poisoning are similar to all classes of livestock. See the information in general notes under Cicutamaculata.
Horses
General symptoms of poisoning:
Bloat, coma, convulsions, death by asphyxiation, lesions, no specific, muscle spasms, muscle twitching, nervousness, salivation, teeth grinding.
Humans
General symptoms of poisoning:
Coma.
Notes on poisoning:
Toxicity and death in humans is possible with all three species of the genus Cicuta(water-hemlock). See the information in the general notes under Cicutamaculata.
Sheep
General symptoms of poisoning:
Bloat, coma, convulsions, death, death by asphyxiation, gait, unsteady, incoordination, lesions, no specific, mouth, frothing of, muscle spasms, muscle twitching, nervousness, salivation, tarsal joint knuckling, teeth grinding, trembling, urination, frequent.
Swine
General symptoms of poisoning:
Coma, convulsions, death by asphyxiation, muscle spasms, muscle twitching, nervousness, salivation.
