POISON IVY
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Toxicodendron radicans   (L. ) Kuntze
[=Rhus radicans L.]
Konza Prairie, Riley County, Kansas
Height: 1-3 feet or climbing to 50+ feet
Family: Anacardiaceae - Cashew Family
Flowering Period:   May
Also Called: Eastern poison ivy.
Trunks: Low erect shrub or vine climbing by aerial roots; bark gray, rough; older bark brown; aerial roots red or brown.
Twigs: Slender, flexible, hairy, tan; buds flattened, pointed or blunt, covered with tan hairs; leaf scars broad, crescent-shaped.
Leaves: Alternate, palmately 3-foliolate, deciduous; stalk 2.5 to 6+ inches long; leaflets 3, egg-shaped to elliptic, 1.6 to 6+ inches long, 1.6 to 4+ inches wide; lateral leaflets smaller, often unequal; upper surface yellow-green, dull, glabrous to sparsely pubescent; lower surface glabrous to soft- or stiff-hairy, often with curly hairs along mid-vein; margins mostly irregularly toothed, lobed or incised; tip pointed to tapering sharp-pointed; base rounded; stalk of terminal leaflet 3/5 to 2 inches long; lateral leaflet stalks shorter.
Flowers: Male and female flowers on separate plants (dioecious); inflorescences grape-like clusters 1.6 to 4.8 inches long; flowers numerous, tiny; sepals 5, about 1/20 inch long, united below, lower half greenish, upper half cream-colored; petals 5, narrowly elliptic, about 1/10 inch long, cream-colored, often with purple veins; stamens 5; anthers yellow; stigma 3-lobed.
Fruit: September; drupe, spherical, 1/6 to 1/5 inch in diameter, hard, glabrous, initially green, turning cream or tan, 1-seeded; seed 2-lobed, yellowish.
Habitat: Dry or moist woods, stream banks, pond and lake margins, roadsides, prairie thickets, shaded, disturbed areas.
Distribution: East 2/3 of Kansas
Origin: Native
Toxicity: All parts of this plant can cause allergic dermatitis when in contact with skin. A red rash, blisters and itching typically occur within 12 to 24+ hours and can spread if the resinous oil is not washed off. Contact with contaminated clothing or animal hair can cause symptoms. Some people are more sensitive than others. One should immediately wash with cold water after contact.
Comments: Poison ivy is highly variable. It is shrub-like in open areas but but in woods climbs via stout aerial roots up to 4 inches in diameter. The wood is soft, porous, yellowish-brown. Toxicodendron rydbergii occurs in the west 2/3 of Kansas.

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