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Identification of Poison Ivy, Poison Oak, Poison Sumac, and Poisonwood
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Permanent Link: http://ufdc.ufl.edu/IR00000834/00001
 Material Information
Title: Identification of Poison Ivy, Poison Oak, Poison Sumac, and Poisonwood
Physical Description: Fact Sheet
Creator: Brown, Sydney Park
Grace, Patricia
Publisher: ■University of Florida Cooperative Extension Service, Institute of Food and Agriculture Sciences, EDIS
Place of Publication: Gainesville, Fla.
Publication Date: 2012
 Notes
Abstract: Florida parks and woodlands are favorite places for many people who enjoy outdoor activities. Unfortunately, the native plants poison ivy, poison oak, poison sumac, and poisonwood can make these outings a miserable experience. All four contain urushiol, a plant oil that can cause a severe skin rash (dermatitis) when any part of the plant is contacted. Allergic reaction can occur directly by touching the plant or indirectly by coming into contact with the oil on animals, tools, clothes, shoes, or other items. Even the smoke from burning plants contains oil particles that can be inhaled and cause lung irritation. This 6-page fact sheet helps individuals learn to identify these plants in order to avoid contact with them. Children should be taught to recognize these plants, particularly poison ivy, as it is by far the most common.
Acquisition: Collected for University of Florida's Institutional Repository by the UFIR Self-Submittal tool. Submitted by Diana Hagan.
Publication Status: Published
General Note: "ENH886"
 Record Information
Source Institution: University of Florida Institutional Repository
Holding Location: University of Florida
Rights Management: All rights reserved by the submitter.
System ID: IR00000834:00001

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ENH886 Identication of Poison Ivy, Poison Oak, Poison Sumac, and Poisonwood1Sydney Park Brown and Patricia Grace2 1. This document is ENH886, one of a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date April 2003. Revised March 2012. Visit the EDIS website at http://edis.ifas.u.edu 2. Sydney Park Brown, associate professor and consumer horticulture Extension specialist, Environmental Horticulture Department, Gulf Coast Research and Education Center, Wimauma, FL 33598; Patricia Grace, former Extension horticulture agent, Putnam County; Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, FL 32611. The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or aliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer-Chancy, Interim DeanIntroductionFlorida parks and woodlands are favorite places for many people who enjoy outdoor activities. Unfortunately, the native plants poison ivy, poison oak, poison sumac, and poisonwood can make these outings a miserable experience (Figure 1). All four contain urushiol, a plant oil that can cause a severe skin rash (dermatitis) when any part of the plant is contacted. Allergic reaction can occur directly by touching the plant or indirectly by coming into contact with the oil on animals, tools, clothes, shoes, or other items. Even the smoke from burning plants contains oil particles that can be inhaled and cause lung irritation. Individuals vary in their susceptibility to these plants. Some people are not sensitive but may become sensitive aer repeated exposure. Symptoms appear within 8 hours and can last for weeks. Itching and burning of the skin may be followed by a rash, redness, swelling, and watery blisters. e rash, which can last 2 weeks, is not contagious and will not spread. Systemic complications can occur if the blisters become infected. Over-the-counter skin creams containing the active ingredient bentoquatam (for example, Ivy Block) absorb the urushiol oil and can prevent or lessen a reaction if applied before contact. If exposed to the urushiol oil in one of these plants, immediately cleanse exposed skin, tools, shoes, or other items with plenty of warm, soapy water and then rinse thoroughly with plain, cool water. Clothes should be washed thoroughly and separately from other laundry. Minor rashes can be cared for at home with over-the-counter treatments that contain zinc acetate, hydrocortisone, or zinc oxide; oatmeal baths; a paste of baking soda; or oral antihistamines. Severe or infected rashes may need professional medical treatment. Figure 1. Poison ivy Credits: (Source: Cook 2012)

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2 Interaction with these plants is largely preventable. is publication helps individuals learn to identify these plants in order to avoid contact with them. Children should be taught to recognize these plants, particularly poison ivy, as it is by far the most common. Keep in mind that poison ivy, poison oak, and poison sumac are deciduous, making identication dicult in winter. Nevertheless, the sap from leaess stems and roots is still problematic. Other poison ivy relatives that grow in Florida and may also cause allergic reactions include mango ( Mangifera indica ) (http://edis.ifas. u.edu/mg216), cashew (Anacardium occidentale ) (http:// edis.ifas.u.edu/hs377), and the highly invasive Brazilian pepper-tree (Schinus terebinthifolius ) (http://edis.ifas.u. edu/aa219).Poison Ivy (Toxicodendron radicans)Poison ivy grows in shady or sunny locations throughout Florida. It can be a woody shrub up to 6 feet tall or a vine up to 150 feet tall that climbs high on trees, walls, and fences or trails along the ground (Figure 2). All parts of poison ivy, including the hairy-looking aerial roots, contain urushiol at all times of the year, even when bare of leaves and fruit in winter. Plants are frequently abundant along old fence rows and the edges of paths and roadways. Leaf forms are variable among plants and even among leaves on the same plant; however, the leaves always consist of three leaets. e old saying Leaets three, let it be is a reminder of this consistent leaf characteristic. Leaets can be 2 inches long and may be toothed or have smooth edges. e stem attaching the terminal leaet is longer than stems attaching the other two. Leaves emerge with a shiny reddish tinge in the spring and turn a dull green as they age, eventually turning shades of red or purple (Figure 3) in the fall before dropping. Flowers and fruit are always in clusters on slender stems that originate in the leaf axils, or angles, between the leaves and woody twigs. e berrylike fruits are round and grooved with a white, waxy coating. ey are attractive to birds. e leaves and fruit are an important food source for deer (Figure 4). A common poison ivy look-alike is the native Virginia creeper (Parthenocissus quinquefolia ) (Figure 5). is trailing or climbing vine can be distinguished from poison ivy rather easily by its ve divided palmate leaets. Other distinguishing features include blue-black berries and Figure 2. Poison ivy leaves (consisting of three leaets) and owers Credits: UF/IFAS Center for Aquatic and Invasive Plants Figure 3. Poison ivy vine showing single leaf (in circle) and fall red color Credits: Dan Culbert, UF/IFAS Figure 4. Poison ivy mature fruits Credits: (Source: Cook 2012)

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3 tendrils that end in tiny sticky pads that attach to trees and other surfaces. In winter, the leaves of Virginia creeper turn red and drop from the plant (Figure 6). For more information, see http://edis.ifas.u.edu/fp454.Poison Oak (Toxicodendron pubescens)Poison oak, also known as Atlantic poison oak, oakleaf ivy, or oakleaf poison ivy, is a low-growing, upright shrub that is about 3 feet tall. It is found in dry, sunny locations and does not tolerate heavy shade. Poison oak is conrmed in North and Central Florida, from Levy and Marion Counties northward. Like poison ivy, a single poison oak leaf consists of three leaets. e stem attaching the terminal leaet is longer than the stems attaching the other two. One distinguishing feature of poison oak is its lobed leaves, which give it the appearance of an oak leaf. e middle leaet usually is lobed alike on both margins, and the two lateral leaets are oen irregularly lobed (Figure 7). Leaf size varies consider ably, even on the same plant, but leaves are generally about 6 inches long. Another distinguishing feature is that the leaf stems and leaets have a coating of ne hair. Leaets emerge with a reddish tinge in the spring, turn green, and then assume varying shades of yellow and red in the fall before dropping. As with poison ivy, the owers and fruit arise from the leaf axils in clusters. e small owers are white, and the ripe fruit is round, light tan, waxy, and grooved (Figure 8). Figure 5. Virginia creeper Credits: Larry Korhnak, UF/IFAS Figure 6. Virginia creeper showing vining habit and winter color Credits: Sydney Park Brown, UF/IFAS Figure 7. Poison oak lobed leaves and immature green fruit Credits: Larry Korhnak, UF/IFAS

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4 Poison Sumac ( Toxicodendron vernix)More allergenic than poison ivy and poison oak is poison sumac, a deciduous woody shrub or small tree that grows 5 feet tall and has a sparse, open form (Figure 9). It inhabits swamps and other wet areas, pine woods, and shady hardwood forests. In Florida, poison sumac has been conrmed in the north and central regions, as far south as Polk County. Poison sumac leaves consist of 7 leaets arranged in pairs with a single leaet at the end of the midrib. Distinc tive features include reddish stems and petioles (Figure 10). Leaets are elongated, oval, and have smooth margins. ey are 2 inches long, 1 inches wide, and have a smooth, velvety texture. In early spring, the leaves emerge bright orange. Later, they become dark green and glossy on the upper leaf surface and pale green on the underside. In the early fall, leaves turn a brilliant red-orange or russet shade. e small, yellowish-green owers are borne in clusters on slender stems arising from the leaf axils. Flowers mature into ivory-white to gray fruits resembling those of poison oak or poison ivy, but they are usually less compact and hang in loose clusters of up to 10 inches in length (Figure 11). Figure 9. Poison sumac Credits: (Source: Cook 2012) Figure 10. Poison sumac leaets, reddish stems, and immature green fruit Credits: Larry Korhnak, UF/IFAS Figure 11. Poison sumac mature fruit in winter Credits: (Source: Cook 2012) Figure 8. Poison oak mature fruit Credits: (Source: Cook 2012)

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5 Winged sumac ( Rhus copallinum) has a similar appearance but is a nonallergenic relative that grows throughout Florida. It can be distinguished from poison sumac most readily by its 9 leaets, clusters of red berries, and the winged rachis between the leaets (Figure 12).Poisonwood (Metopium toxiferum)Poisonwood is an evergreen shrub or tree that grows 25 feet tall in hammocks, pinelands, and sandy areas near saltwater. It is particularly abundant in the Florida Keys. As of this writing, poisonwoods range has only been conrmed in ve counties in South Florida: Martin, Palm Beach, Broward, Miami-Dade, and Monroe. e tree has a spreading, rounded form with a short trunk and arching limbs with drooping branches. e bark varies in color from reddish brown to gray, depending on the habitat, and has oily patches of sap on the surface; older trees have scaly bark (Figure 13). Each leaf is comprised of three to seven oval leaets, although ve leaets are typical. Leaves are glossy and dark green above and paler underneath. e smooth edges are thick and curl under slightly. Irregular blotches of resin dot the surface of many of the leaets (Figure 14). e fruit is inch long, oval, yellow to orange in color, and hangs in loose clusters (Figure 15). e poisonwood fruit is an important food source for the threatened white crown pigeon. Do not walk where poisonwood is known to grow during a rainstorm. Rainwater dripping o the poisonwood leaves contains urushiol, which causes contact dermatitis. Figure 12. Winged sumac Credits: Larry Korhnak, UF/IFAS Figure 13. Poisonwood bark variations Credits: Kim Gabel, UF/IFAS Figure 14. Poisonwood leaves with dots of resin Credits: Kim Gabel, UF/IFAS Figure 15. Poisonwood fruit Credits: Larry Korhnak, UF/IFAS

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6 Acknowledgements e author wishes to thank Mary Derrick, horticulture program assistant, for her help with the research and editing of this publication, and Dan Culbert, Okeechobee County Extension agent, as well as Kim Gabel, Monroe County Extension agent, for their reviews and contributions.ReferencesCook, W. 2012. Trees, Shrubs, and Woody Vines of North Carolina. Accessed February 2012. http://www.duke. edu/~cwcook/trees/.Additional ResourcesCenters for Disease Control and Prevention. 2012. Poisonous Plants. Accessed March 2012. http://www.cdc.gov/ niosh/topics/plants/ Hossler, E. W. 2010. Botanical Briefs: Poisonwood (Meto pium toxiferum ). Cutis 85(4) 178. Institute for Systemic Botany. 2012. Atlas of Florida Vascular Plants. Accessed February 2012. http://orida. plantatlas.usf.edu/. Mayo Clinic Online. 2012. Poison Ivy Rash. Accessed March 2012. http://www.mayoclinic.com/health/ poison-ivy/DS00774. MedLine Plus. 2012. Poison Ivy Oak Sumac Rash. Accessed February 2012. http://www.nlm.nih.gov/medlineplus/ency/article/00y0027.htm. Nellis, D. W. 1997. Poisononus Plants and Animals of Florida and the Caribbean Sarasota, FL: Pineapple Press. UF/IFAS (University of Florida Institute of Food and Agricultural Sciences). 2012. Forest Trees and Companion Plants. Accessed March 2012. http://www.sfrc.u.edu/4h/ Trees_Plants/trees_plants.html