POISONOUS PLANTS, Plants which contain poisonous substances in sufficient amounts to render them injurious when eaten or touched by men or animals. There is, how ever. no sharp line of distinction between poison ous and non-poisonous plants. Many harmless plants, even some of our most wholesome food like the potato, contain traces of sub stances.which in a concentrated extract are violent poisons. Others, though really harmless unless eaten in immoderate quantities. are or have been popularly reputed to be poisonous. There are, however, a number of plants of which moderate doses are known with certainty to produce in jurious or even fatal results. A botanical classification of these would scarcely be con venient, as they are scattered nearly through out the vegetable kingdom. Yet it is a notice able fact that certain natural families are es pecially rich in poisonous members. whose active principles are characteristic of the family. Thus nearly all members of the Solanacere and Papa veraeter contain narcotic alkaloids; convulsive and cardiac neurotic poisons are characteristic of the Apoeynacex and Loganiace:r ; prussic acid is frequent in the seeds and foliage of the Drupace:e: oils and acids producing cutaneous irritation are characteristic of the Anacardincece. Euphorbiacex, and Urticacefe: the Iridacex, Liliaeece, Ilanunculace:c, Papilionaeefe (Legu minosic Umbellifera-, and l'ucurbitacKe are also notable for their poisonous members.
though several of these are equally notable for their food plants.
The poisonous members of the .Anacardiacere. Such as the poison sumac and poison ivy, are the most important of the plants which are poison ons to the touch, producing inflammation of the skin: most of the others are poisonous only when eaten. Of these some contain the active principle chiefly in the fruit or seed, such as belladonna. bittersweet, stramonium, poke. hen bane. etc.: in others, such as water hemlock and aconite, it is chiefly concentrated in the roots or tubers, though in hemlock, as in many other cases, every part of the plant i- almost equally poison ous. In suet] plants as ailanthus, kalini:i, and wild cherry, the foliage is especially poisonous, and the latter two have often been fatal to live stock. See the separate articles on the families and individual plants named, and the article FUNti I. EDILLE AND PoISONOUS. Consult: V. h. Chestnut. Thirty Poisonous Plants of the Unitcd States. in Farmers' Itulletin S6, United States Department of Agriculture.