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Poisonous Alkaloids

Nearly all of the alkaloids mentioned so far are poisonous in large amounts. Some alkaloids, however, are almost solely known as poisons. One of these is strychnine, derived from the small Hawaiian tree Strychnos nux-vomica. Symptoms of strychnine poisoning begin with feelings of restlessness and anxiety, proceeding to muscle twitching and exaggerated reflexes. In severe poisoning, a loud sound can cause severe muscle spasms throughout the entire body. These spasms may make breathing impossible and result in death.

In the early part of the twentieth century, strychnine was widely used as a rat poison. In recent decades, however, slower-acting poisons have been used for rodent control; since rats can remember which foods have made them sick, one that receives a non-fatal dose of a fast-acting poison such as strychnine will never again take that type of poisonous bait.

A number of other plants also derive their lethal properties from alkaloids of one type or another. Among these are poison hemlock (Conium maculatum) and plants of the genus Aconitum, commonly called monkshood—known by devotees of werewolf stories as wolfsbane. Other examples include shrubs of the genus Calycanthus, known as Carolina allspice, spicebush, and sweet betty, among other names; vines of the genus Solandra, such as the chalice vine, cup-of-gold, silver cup, and trumpet plant; trees or shrubs of the genus Taxus, such as yews; plants of the lily-like genus Veratrum, including false hellebore; and the golden chain or bean tree (Laburnum anagyroides).

Although vines and non-woody plants of the genus Solanum pose a real danger only to children, they represent an extremely varied group. Poisonous members of this genus range from the common potato to the nightshade (not the same as the deadly nightshade that produces atropine). The group also includes the Jerusalem cherry, the false Jerusalem cherry, the love apple, the Carolina horse nettle, the bittersweet, the nipplefruit, the star-potato vine, and the apple of Sodom.

Poisoning by ordinary potatoes usually results from eating uncooked sprouts or sun-greened skin. These parts should be cut away and discarded. For other plants in the group, it is the immature fruit that is most likely to be poisonous. In contrast to the nervous-system effects of most alkaloids, the alkaloids found in the genus Solanum produce mainly fever and diarrhea.



Lampe, Kenneth F., and Mary Ann McCann. AMA Handbook of Poisonous & Injurious Plants. Chicago: Chicago Review Press, 1985.

Pelletier, S. W. Alkaloids: Chemical and Biological Perspectives. New York: John Wiley & Sons, 1983.

W. A. Thomasson

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