This section is from the book "A Guide To The Poisonous Plants And Weed Seeds Of Canada And The Northern United States", by Robert Boyd Thomson, H. B. Sifton. Also available from Amazon: A guide to the poisonous plants and weed seeds of Canada and the northern United States.
Although this section consists of plants that have rarely been observed to cause the death of animals, and so may be thought of secondary importance to the veterinarian, farmer and stockman, yet animals may under exceptional circumstances be poisoned by them. Indeed, the aggregate loss from their agency is very considerable, and diagnosis should not be considered complete until this section has been consulted. Included among them are some of the most virulently poisonous of plants, e.g., the "Death Cup" mushroom, whose baneful effects on human beings are widely known. Others contain epidermal poisons so strong that death has been reported to have resulted from mere contact with the bruised plants. Still others are the source of medicinal drugs. On this account and because, as pointed out in the introduction, Section IV contains by far the larger proportion of the plants that are poisonous to human beings, this section should prove of especial interest to medical men.