Eastern poison ivy
Toxicodendron radicans
Eastern poison ivy,Poison ivy,Poison oak
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Description
Numerous subspecies and/or varieties of T. radicans are known, which can be found growing in any of the following forms; all of which have woody stems: as a climbing vine that grows on trees or some other support as a shrub up to 1.2 m (3 ft 11 in) tall as a trailing vine that is 10–25 cm (4–10 in) tallSubspeciesT. r. subsp. barkleyi Gillis T. r. subsp. divaricatum (Greene) Gillis T. r. subsp. eximium (Greene) Gillis T. r. subsp. hispidum (Greene) Gillis T. r. subsp. negundo (Greene) Gillis T. r. subsp. pubens (Engelm. ex S. Watson) Gillis T. r. subsp. radicans T. r. subsp. verrucosum (Scheele) GillisThe deciduous leaves of T. radicans are trifoliate with three almond-shaped leaflets. Leaf color ranges from light green (usually the younger leaves) to dark green (mature leaves), turning bright red in fall; though other sources say leaves are reddish when expanding, turn green through maturity, then back to red, orange, or yellow in the fall. The leaflets of mature leaves are somewhat shiny. The leaflets are 3–12 cm (1.2–4.7 in) long, rarely up to 30 cm (12 in). Each leaflet has a few or no teeth along its edge, and the leaf surface is smooth. Leaflet clusters are alternate on the vine, and the plant has no thorns. Vines growing on the trunk of a tree become firmly attached through numerous aerial rootlets. The vines develop adventitious roots, or the plant can spread from rhizomes or root crowns. The milky sap of poison ivy darkens after exposure to the air. The urushiol compound in poison ivy is not a defensive measure; rather, it helps the plant to retain water. It is frequently eaten by animals such as deer and bears. T. radicans spreads either vegetatively or sexually. It is dioecious; flowering occurs from May to July. The yellowish- or greenish-white flowers are typically inconspicuous and are located in clusters up to 8 cm (3 in) above the leaves. The berry-like fruit, a drupe, mature by August to November with a grayish-white colour. Fruits are a favorite winter food of some birds and other animals. Seeds are spread mainly by animals and remain viable after passing through the digestive tract. T. radicans vine with typical reddish "hairs": Like the leaves, the vines are poisonous to humans. T. radicans in Perrot State Park, Trempealeau County, Wisconsin Flower detail, with bee Poison ivy on a roadside Leaves may be smooth or notched on the same plant.
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Taxonomy
Order
Sapindales
Family
Anacardiaceae
Genus
Toxicodendron
Characteristics
Bloom Time
Spring, Apr, May, Jun
Plant Type
Native Plant, Poisonous, Shrub, Vine, Weed
Lifespan
Perennial, Woody
Flower
Across from the compound leaves, panicles of yellowish green flowers are sparingly produced. These panicles are up to 4 inches long and across; they are often irregular in shape. Each flower is about ¼ inch across, consisting of 5 green petals, 5 stamens, 5 sepals, and an ovary with a stout style. The petals are triangular-shaped and recurved, while the sepals are smaller in size and deciduous.
Fruit
Each flower is replaced by a drupe that contains a single seed (stone). This drupe is dull white and about ¼ inch across; it has a smooth waxy surface. The large seed is ovoid in shape and dull white; there are a few grey stripes across its surface. The drupes mature during the fall and can persist through the winter., Amber 1/4 inch diameter.
More Info
How to Grow
Sunlight
Dappled Sunlight (Shade through upper canopy all day), Full sun (6 or more hours of direct sunlight a day), Partial Shade (Direct sunlight only part of the day, 2-6 hours), Part Shade, Shade
Benefits
Attracts
Butterflies
Moths
Songbirds
Warning
POISONOUS PARTS: All parts, in all seasons if plant sap contacted. Severe skin irritation upon contact. Symptoms include severe skin redness, itching, swelling, and blisters following direct or indirect contact. Toxic Principle: Urushiol.