Other significant names given to this plant are beaver-poison, spotted cowbane, musquash-root, snakeweed, and chil-dren's-bane.
The water hemlock is a tall perennial herb from three to six feet in height. The stem is stout and streaked with purple. The leaves are compound, but not so finely divided as in the poison hemlock (cf. illustrations). The leaflets are saw-toothed. The small white flowers are arranged in a compound umbel with no bracts at the base of the main umbel. There are slender bracts at the base of each lesser umbel or umbellet. The fruit is oval, with no groove on the inner face of the seed. The roots are several, fleshy, in the form of oblong tubers clustered at the base of the stem. If the base of the stem is cut lengthwise, a number of transverse partitions will be seen in greater or less contiguity according to the time of year and growth. The plant is in bloom from June to August.
Water hemlock, unlike poison hemlock, is found in wet places, in swamps, low ground, and along streams. Native of Canada, it is common from New Brunswick to British Columbia.
Of all the poisonous plants in Canada, the water hemlocks are the most deadly and act most rapidly. All species of cicuta are exceedingly poisonous both to human beings and animals. Although there is some difference of opinion as to the amount of toxicity in the upper portion of the plant, yet all agree the roots and swollen base of the stem are the most virulent. They are usually eaten by animals early in the season, when they offer an abundant green fodder. As they grow on wet, soft land, the roots are easily pulled up by stock when eating the herbage. The toxic principles are the alkaloid cicutine, with oil of cicuta and cicutoxine, a bitter resinous substance.
Photo - F. Fyles.
No animals appear to be immune to the poisonous effect of this plant. Cattle and sheep, however, suffer most, as in grazing they pull the roots up and eat them as well. Hedrick says that a piece of root the size of a walnut was found by experiment to be sufficient to kill a cow. Death may occur in fifteen minutes, or the intense suffering may continue from two to several hours before death. One of our correspondents from Alberta writes: "These are the plants (C. vagans) that killed the cattle in that neighbourhood, and the cattle would eat them and gnaw a hole in the ground like a bowl to get the roots, and then die right there. There were the bones of some of the cattle poisoned last year within ten feet of where these plants that I am sending you were growing."
Cases of human poisoning are too numerous and too widespread to mention in detail. Different parts of the water hemlock have been eaten by mistake for edible plants, the roots especially being often mistaken for artichokes or sweet potatoes. The tubers are especially tempting to children on account of their sweetish taste.
The first symptoms usually occur within two hours after eating the plant. There is nervousness, twitching of the muscles of the mouth and ears, salivation, sometimes nausea and vomiting, bloating, intense pain, frenzied movements, dilated pupils, spasms and convulsions, frothing at the mouth and nose, twisting the head and neck backwards, rolling of the eyeballs. The victim usually dies in the most violent spasms.