GARDENING : WATCH FOR POISONS IN OUR PLANTS.

Byline: Joshua Siskin

Although few people die from plant poisoning, it is a good idea to be aware of which plants are toxic, especially when small children - who put almost everything into their mouths - are playing outside.

``Poisonous Plants of Southern California,'' a new booklet published by the Department of Recreation and Parks of Los Angeles County, contains artistic black-and-white renderings of 84 plants. The toxic parts of each species are indicated, as well as the symptoms of poisoning. Among the plants described are some of the most commonly seen ornamentals, including lily-of-the-Nile (Agapanthus) and iris. You learn that the leaves and rhizomes (semi-underground bulb-like structures) of both plants are toxic.

From a cursory perusal booklet, it would appear that one family of plants is especially notable for its toxicity: the nightshade family (Solanaceae). Among the toxic nightshades are two staples of our diet, and one spicy side dish, all three of which are native to South America - the tomato, the potato and the chili pepper. The leaves and stems of tomatoes and potatoes are poisonous. Also, consumption of potato skins that are green in color should be avoided. Chili pepper fruits (jalapenos) are labeled toxic, although one of the listed symptoms - ``irritation of the mouth and throat'' - will not deter lovers of these hot delicacies.

Poisonous ornamental nightshades include tree datura or angel's trumpet (Brugmansia), Jerusalem cherry (Solanum pseudocapsicum), night-blooming jasmine (Cestrum nocturnum) and deadly nightshade or belladonna (Atropa belladonna).

The pea or legume family (Fabaceae) is also well represented in this booklet. Seeds of the black locust (Robinia), poinciana (Caesalpinia), coral tree (Erythrina), sweet pea (Lathyrus) and wisteria vine are all poisonous. Seeds of the fava bean - another legume - are considered quite tasty by vegetable gourmets but may be toxic to some people from Mediterranean countries.

Many of our most familiar garden and landscape trees, shrubs, ground covers and bulbs are poisonous. These plants and their toxic parts include: English ivy (leaves and berries), Delphinium and foxglove (all parts), Hydrangea (all parts), oak (raw acorns), oleander (all parts), apple, plum and peach (leaves and seeds), privet (leaves and berries), azalea (all parts), bird-of-paradise (seeds and pods), columbine (seeds), chinaberry (all parts), crown-of-thorns and pencil tree (milky sap), euonymous (leaves, bark, seeds), holly (berries), daffodil, hyacinth, naked lady (bulbs) and pregnant onion (all parts).

Although St. John's wort is renowned as an antidepressant, you won't feel any better by making a tea out of it, since all of its parts are toxic. You would need to carefully follow the steps of St. John's wort pharmacological processing in order to derive any medical benefit from it.

Many houseplants are poisonous, including all the philodendrons and pothos, that most popular indoor plant with heart-shaped green and yellow leaves and trailing growth habit. Dieffenbachia is also toxic.

Tip of the week: If you think someone has been poisoned by a plant, call [phone]. You will be asked to identify the plant as well as the part and the quantity consumed. If you are concerned that certain plants in your yard or garden might be poisonous, make an appointment with the L.A. County Arboretum for their identification by calling [phone].