Toxic plants and animals. Organisms containing natural products which upon contact with humans or animals cause allergic or toxic reactions, in extreme cases death. Their toxicity is a chemical rather than physical means of natural defense.

Toxic plant substances common in Ukraine can be categorized according to the organic processes they affect: the central nervous system (ben-bane, Indian poke, greater celandine, colchicum), the respiratory and digestive system (nasturtium and yellow rhododendron), the gastrointestinal system (milkwort, water dropwort, cockle, nightshade, spurge flax, and some mushrooms), the cardiovascular system (digitalis, foxglove, and lily of the valley), the liver (ragweed and heliotrope), and cellular respiratory processes (flax, almonds, and various sensitizers, including buckwheat and Saint-John's-wort). Some naturally toxic plants serve as sources for medicinal preparations (see Medicinal plants). Many modern drugs were first discovered through folk medicine therapies based on various herbs.

There are few life-threatening toxic animals in Ukraine; only some snakes and some Black Sea fish (eg, ruff) are truly toxic. The bites of other animals—scorpions, tarantulas, Scolopendra centipedes, bees, wasps, hornets—may be very painful and may cause excessive swelling but rarely result in death. The venom of some animals has medicinal value.

Ihor Masnyk

[This article originally appeared in the Encyclopedia of Ukraine, vol. 5 (1993).]