KNOW YOUR PLANTS BEFORE YOU TOUCH, TASTE

Poison ivy contains urushios, which causes an itchy rash for people allergic to it.

Doug Newman, a natural history regional biologist, showed an elderberry plant found on a trail at Cape Girardeau County North Park. The plant's bark, twigs, leaves and shoots are toxic, but its ripe fruits are edible.

"Leaves of three, let them be," is an old adage that is still true today.

Avoidance is the best way to prevent "poison ivy" dermatitis, the itchy rash that occurs as a result of contact with poison ivy.

Doug Newman, natural history regional biologist at the Missouri Department of Conservation in Cape Girardeau, said poison ivy is the major plant to avoid in this area.

"People in this area confuse poison ivy with fragrant sumac and Virginia creeper, which are nonpoisonous," Newman said.

The terms poison ivy and poison oak are often applied to poison ivy. Poison oak is a low shrub with oak-like leaves. It is never a climber. Poison oak grows only in the southern-most counties of Missouri near the Arkansas border and is not common there.

Poison ivy can be either a vine with aerial roots, climbing high into trees, or a shrub to 10 feet high. The leaves are three-divided, with the two laterals on short stems and the middle on a much longer stalk.

Urushiol is the irritant in poison ivy that causes a reaction in those allergic to it. If you know you are going to be brushing against a plant with urushiol oil, protect yourself by covering your skin. The oil cannot penetrate clothing, so wear long sleeves, long pants and gloves.

The rash associated with poison ivy can be visible within a few hours after contact and can last for several days or weeks.

The rash is not contagious but the resin that causes the rash is. Touching the resin can spread it to other parts of the body or other people.

If contact does occur, washing and removing the resin within the first few minutes after contact may lessen the severity of the rash. The resin can also stick to clothing for several days. To avoid re-exposure, anything worn at the time of contact should be washed before being used again.

A publication of the Center for Corporate Health notes that for normal outbreaks of poison ivy, there are several ways you can ease the itching. Calamine lotion or hydrocortisone creams available over the counter afford temporary relief. Aspirin and antihistamine are also useful. A hot shower can cause histamines to be released and ease the itch for a few hours.

Special care should be taken in the removal of poison ivy. The plant should not be burned because the urushiol oil can be inhaled in the resulting smoke and cause an internal outbreak.

Some plants can also cause illness if they are eaten. There are more than 300 wild plants in Missouri that are potentially poisonous, and some of them resemble edible species. With the curiosity of children and the current interest in back-to-nature living, the potential for plant poisoning is increasing.

Newman said some of the toxic plants in this area are red buckeye, nightshade, poison hemlock, jimsonweed, jack-in-the pulpit and American holly. The stems and leaves of tomatoes and the leaves of rhubarb are toxic and should be avoided. Also, poppies, philodendron, ivy, azalea, poinsettia and mistletoe are poisonous if eaten. One of the most poisonous is castor beans.

The castor is an attractive ornamental and is often grown around homes. The seeds are extremely toxic. One to three can be fatal to a child. The seeds can be safely grown by removing the flower stalks before the seeds mature.

Water hemlock and poison hemlock both resemble wild carrots and are deadly. Accidental poisoning has occurred when children used the stems for peashooters. Both hemlocks are common in Missouri, where they grow in roadside ditches and fields and along ponds and streams.

Pokeweed has both edible and poisonous parts. The young leaves are cooked as greens, the tender young stems make a good vegetable, and the ripe berries have been used in wine and jellies. All must be cooked. Raw poke is mildly poisonous and can cause stomach cramps and diarrhea. Pokeweed roots are poisonous, cooked or not. The green berries and seeds are also reported to be toxic.

Elderberry bark, twigs, leaves and shoots should be avoided. Children have been poisoned by chewing on whistles and popguns made from the stems. The flowers and ripe fruits are edible and make delicious wine and jelly.

Several species of poisonous plants throughout Missouri are commonly found in pastures and are toxic to livestock.

A science and technology guide published by the University of Missouri Extension Division notes that plants poisonous to livestock include jimsonweed, snow-on-the-mountain and wild indigo, which are commonly found in open areas of pastures.

Shade-loving species include white snakeroot, bracken fern, pokeweed and buckeye. Black nightshade and water and poison hemlock grow along creeks or ditch banks.

Poisonous plants found in cultivated fields include cocklebur, jimsonweed, milkweed, pigweed and Johnson grass. Wild cherry, poison ivy and milkweed are found along fences and hedgerows.

The common cocklebur is most poisonous shortly before reaching the two-leaf stage. During this period of growth, cocklebur is exceedingly toxic to pigs but can also harm cattle and sheep.

If poisoning is suspected, a veterinarian should be called immediately.

Poisonous plants can be identified by area agronomists. These plants should be removed by mowing or by applying a recommended herbicide before turning livestock into the area.

Most of the poisonous plants found in Missouri produce symptoms that are not severe. If you know the plants you come in contact with and don't experiment with unknowns, you should be able to enjoy nature without worry.