293 Toxicodendron radicansCommon Names: poison-ivy, poison ivy Family: Anacardiaceae (cashew Family)
"Leaflets three - let it be!" aptly describes this woody vine with 2-4 in (5-10 cm) leaflets in groups of three. Poison ivy clings to tree trunks and other vertical surfaces with hairlike aerial rootlets which grow out of the stem. If a climbing surface isn't available, poison-ivy will grow as a free-standing shrub that looks a lot like its relative poison oak (T. pubescens). The attractive white berries are 1/4 in (0.6 cm) in diameter. These hang in clusters and are relished by birds. The leaves of poison-ivy turn shades of red and purple in fall.
Toxicodendron radicans is native throughout North America east of the Rockies where it grows almost anywhere, in forests, swamps and fields.
CultureYou may already have poison-ivy in your landscape whether you want it or not. The seeds are spread by birds and the woody vine clings tightly to tree trunks. Light: Poison ivy seeks maximum sunlight by climbing. Moisture: Not particular. Hardiness: USDA Zones 3 - 10. Propagation: By seed
Poison-ivy should be welcomed in natural areas where its attractive white berries will be appreciated by many kinds of birds and the plant won't be a threat to people sensitive to its toxin.
Many kinds of songbirds relish the berries (unripened ones are shown in the picture). In fall, the foliage turns dramatic shades of purple and red.
Many people are sensitive to the toxins in poison-ivy sap, but others are completely immune. Sensitivity may change, too. People sometimes develop sensitivity to poison-ivy after years of immunity, and vice-versa. The smoke from burning poison-ivy leaves and stems can cause serious irritation to bronchial passages and lungs. Even in winter the leafless stems and vines can cause the familiar skin rash. Dogs and other animals are not effected by poison-ivy, but people can get the rash by petting a dog that's been exposed. If you think you've been exposed to poison-ivy, rinse the affected area with rubbing alcohol as soon as possible. Soap and water will just spread the poison (and the ensuing rash) around. It takes two or three days after contact for the familiar dermatitis to develop. By that time the toxin itself is gone and further spreading is impossible. Familiar skin products like calamine lotion offer some relief from the itching, but nothing feels better than dousing the rash with the hottest water you can stand!