The most familiar of the English names are broad-leaved laurel, poison-laurel, sheep-laurel, spoonwood, calico-bush.
The mountain laurel is one of our most attractive shrubs usually from three to six feet high, but in the Southern States it sometimes attains a height of thirty or forty feet. Its leaves are bright green on both sides, thick, with short stalks, flat and shining, oval, pointed at each end, entire. It has beautiful clusters of showy pink flowers with clammy stalks. The seed-capsule is round, hard, dry, clammy and many-seeded. The plant is in bloom from May to July.
This native plant is found on rocky hills, pastures and mountain slopes from New Brunswick to Ontario.
B. S. Barton (1798) says: "Nearly allied to the Rhododendron is the genus Kalmia. Of this we have several species, and all of them are poisons. The Kalmia Latifolia, or broad-leaved laurel, is best known to us. It kills sheep and other animals. Our Indians sometimes use a decoction of it to destroy themselves."
All parts of the plant except the wood contain the very poisonous constituent andromedotoxin. Many cattle and sheep are poisoned annually by it. Poisoning usually takes place in the spring when the animals, after the dry food of winter, are attracted by its evergreen foliage. Cases of human poisoning have been known from eating the honey from the flowers, or chewing the leaves in mistake for wintergreen. (Chestnut).
The general symptoms as given by Chesnut for sheep, cows, and goats, are as follows: "Persistent nausea, with slight but long-continued vomiting and attempts to vomit, frothing at mouth, grating of teeth, irregular breathing, partial or complete loss of sight and feeling, dizziness, inability to stand, extreme drowsiness, coma and death" * * * "In addition to most of the above effects, there is, in man, severe pain in the head, an increased tendency to perspire, and often a peculiar tingling sensation in the skin throughout the entire body."