NEBRASKAland Magazine is dedicated to outstanding photography and informative writing with an engaging mix of articles and photos highlighting Nebraska’s outdoor activities, parklands, wildlife, history and people.
Issue link: http://mag.outdoornebraska.gov/i/668245
68 NEBRASKAland • MAY 2016 F or instigating itches, blisters, rashes and general discomfort, few plants can compete with poison ivy. Although a fortunate few persons are immune to poison ivy's deleterious effects, more than half the population experiences physical reactions after coming in contact with the plant. The unpleasant results of a "brush" with poison ivy may last for days, weeks or even months. Poison ivy has been irritating people for a long time. In 1609, English adventurer Captain John Smith gave the plant its apt name. He thought it resembled English ivy in appearance, but went on to observe that "the plant causes abominable itchynge (sic)." Poison ivy is a member of the Cashew family (Anacardiaceae). Many Nebraskans have heard of three "poison" members of this family: poison ivy (Toxicodendron radicans), poison oak (Toxicodendron toxocarium) and poison sumac (Toxicodendron vernix). Of the three plants, poison ivy is the most widespread and the only one found in Nebraska. It grows in most types of terrestrial habitat, including swamps, forests and fields. Poison ivy can grow in full sun, as well as in nearly full shade. Preferred habitats include forest edges and recently disturbed open fields. Poison ivy grows in various ways. As a ground cover, it spreads outward and creates a knee-high thicket of foliage. As a freestanding shrub, it can grow as tall as two feet in Nebraska, with one stem and several side branches. As a vine, poison ivy uses brown aerial roots to attach itself to the sides of trees or other objects. In this form, poison ivy reaches its greatest size. It is not uncommon to find vines as thick as your arm growing on trees. "Leaves of three, let them be." This rhyme pertains to the identification of poison ivy and poison oak. Poison ivy has compound leaves; that is, each leaf is made up of distinct parts called leaflets. There is one leaflet at the end of the leaf stalk and two leaflets opposite each other below the first. This is known as a trifoliate pattern. The two lower leaflets have very short stalks and are shaped like mittens. The shape, color and texture of poison ivy leaflets vary. Poison ivy's trademark leaf triads in Nebraska are green in the spring, and remain that color throughout the summer. Although the color of its berries is sometimes mentioned as a way of identifying the plant, fruit color is not as reliable as leaf identification. Also, the berries appear at the end of the growing season – not helpful for identifying poison ivy in the spring. Another wild vine – Virginia creeper – is sometimes mistaken for poison ivy. However, Virginia creeper usually has five leaves to a branch rather than three, and its leaves are more toothed than those of poison ivy. Virginia creeper is not only harmless, but makes for beautiful fall foliage. The second half of that last statement is also true of poison ivy. The green of the plant's leaves in summer yields to brilliant reds, yellows and oranges in the fall. Their autumnal brilliance is due to pigments characteristic of the Cashew family. Poison Ivy Nebraska's Most Irritating Plant By Joe Zenter POISON IVY is identified by its three distinct leaves and can grow as a ground cover, shrub or vine. PHOTO BY NEAL RATZLAFF PHOTO BY DOUG CARROLL