FRIENDS OR FOES? ORNAMENTALS - MEDICINAL PLANTS - POISONOUS PLANTS

Often it is difficult to clearly distinguish between medicinal/poisonous/ ornamental plants. In case of several species, such as lavenders, oreganos and sages, a large number of taxa are available for the cottage garden both as ornamentals and as sources of home remedies. Our investigation directed at the medicinal value of orna-mental sage cultivars revealed that their volatile compounds were the same as those of common sage, only the ratio of components differed. The physiological effect of several plant derivatives is dose-dependent: small doses can be used for therapeutic purposes, while larger doses exert a toxic effect on humans and/or animals. The tropane alkaloids of Datura species, often planted for the decorative value of the flowers, are applied in medicine, but consumption of the plant, either intentionally or accidentally, may lead to intoxication. In our experience not only the various organs of Datura sp., but also the floral nectar contains the alkaloids. Attractive as they are, some of our most popular indoor and outdoor ornamentals are poisonous, being especially dangerous for children, who are inclined to taste various plant parts. According to our survey conducted in Hungarian nurseries and kindergartens, the little ones are exposed to the danger of intoxication by touching or consuming poisonous plants like Laburnum anagyroides, Taxus baccata and Thuja spp., often planted as ornamentals in the playing grounds.