Rhus, The Toxic Family

Poison oak, ivy, and sumac are toxic plants that commonly grow in the United States and Canada. They are members of the plant family called Rhus. These plants are similar in their appearance, growth, and effects on humans. They also respond alike to control efforts and to treatment of a skin condition they inflict.

The plants are most commonly seen along fence rows, open and cut-over forest lands, stream banks, and up tree trunks. In the fall, these species' leaves turn brilliant red and become a tempting target to touch. Many people who are unfamiliar with the plant gather the colorful leaves in the fall and many times suffer acute allergic reactions.

At times hospitalization can be required.

IDENTIFY

Both poison oak and poison ivy are readily identified by their leaves. Shiny when young, the leaves grow in groups of three. Leaflets range from a half-inch to two inches long. Flowers are greenish white, about one-quarter of an inch across and are borne in clusters on a slender stem. The fruits are white, berry-like, glossy and dry when ripe, about one-sixth of an inch in diameter in poison ivy and a little larger in poison oak.

Poison sumac is a little different in that it resembles non-poison sumacs in habitat, bark and leaves. The leaves are approximately twelve inches long with 7 to13 leaflets on a long red petiole. The fruit is also berrylike but smooth.

All parts of these plants except the pollen are poisonous year round. The best way to prevent problems is to avoid contact with the plant.