Florida native plants get a lot of love, but just because a plant is native doesn’t mean it’s necessarily a wanted presence. Native plants like poison ivy, poison oak, poison sumac, and poisonwood can leave you with an irritating souvenir from outdoor adventures.
These plants are well known for the severe skin rash they can cause when people come into contact with them. This irritation is caused by a plant oil called urushiol. You can have a reaction to this oil from touching the plants, but also from touching anything that has come into contact with the plants including animals (like pets), tools, clothes, and shoes. Even the smoke that comes from burning these irritating plants can cause lung irritation.
Toxicodendron radicans — Poison ivy can grow as a woody shrub up to 6 feet tall, but more commonly it grows as a vine that can climb high walls, trees, or fences; it can run along the ground up to 150 feet. All parts of the plant contain the irritating urushiol oil. Even when poison ivy is dormant, with no leaves or fruits on the plant, the urushiol is still present and can irritate skin. While there can be variation in leaf forms and sizes—even on the same plant—the leaves will always have three leaflets. Another vine, called Virginia creeper, is sometimes confused with poison ivy, but Virginia creeper is distinguishable by its five divided leaflets.
Toxicodendron pubescens — Poison oak grows in North and Central Florida, and is an upright shrub that reaches about 3 feet tall. Keep in mind the "leaves of three, let it be" rule, because poison oak also has three leaflets. But unlike poison ivy, poison oak won't be found growing as a vine. These plants grow in sunny areas and don’t tolerate shade.
Toxicodendron vernix — Poison sumac is more likely to cause a reaction than either poison oak or poison ivy. This plant is also found in North and Central Florida, but in swamps and wet areas. Poison sumac leaves have 7 to 13 leaflets that are paired, with one unpaired leaflet at the tip.
Metopium toxiferum — This evergreen shrub or tree can get quite big, 25 to 35 feet tall, and is most likely to be found in hammocks, pinelands, and sandy areas near saltwater. Particularly abundant in the Florida Keys and the Everglades, this plant is only found in South Florida. Poisonwood contains so much urushiol that even rainwater dripping off the leaves contains the irritating oil.
If you're unlucky enough to come into contact with one of these plants, immediately clean exposed skin, tools, shoes, and any other items that might have picked up the oil with plenty of warm, soapy water. Rinse thoroughly with plain, cool water. Wash the clothes you were wearing apart from other laundry, and use hot water. If your rash is mild, you can use over-the-counter treatments that contain zinc acetate, hydrocortisone, or zinc oxide; other home treatments include oatmeal baths, a paste of baking soda, or oral antihistamines. If the rash is severe, or becomes infected, you should see a doctor.