Identify the Perpetrator
Nothing takes the fun out of being outdoors faster than an encounter with poison ivy. It's the cockroach of the plant world: it regenerates readily, it's everywhere, and people loathe it. At least one member of the poison ivy clan (Toxicodendron, formerly Rhus) grows in every state in the continental U.S. Each region has its own varieties of poison ivy or poison oak, but all are perennials in the cashew family, and all cause a rash, blisters, and that unquellable itch. Our guide helps you to identify, search out, and destroy the culprits in their hiding places, and to beat the rap?—uh, rash—even before it strikes.
Poison ivy in summer
"Leaves of three, let them be" is still the best way to identify poison ivy and poison oak. Poison ivy's leaves are pointed.
Poison ivy in fall
Both poison ivy and poison oak grow in sun or shade, in wet or dry places, and turn vivid colors in fall
Poison ivy in winter
The berries are white and are a good identifier once the leaves have fallen off in early winter.
Poison ivy in spring
Poison ivy can grow as a groundcover, a shrub, or a vine. Emerging leaves have a red tint to their edges.
Poison oak's leaflets are rounded. It grows as a vine or shrub.
Poison ivy root
Both poison ivy and poison oak climb trees, sending out thick, hairy, aerial roots.
This native (and harmless) vine is often mistaken for poison ivy, but Virginia creeper has five leaflets, and blue-black berries.
Other Itchy Suspects
Myrtle spurge, or donkey tail
(Euphorbia myrsinites) This ornamental contains a toxic, milky latex that can permanently scar the skin.
(Ruta graveolens) All parts contain a photochemical that causes a heightened reaction to sunlight (photosensitization).
(Centaurea maculosa) This biennial weed causes hives, usually with repeated exposure.
(Pastinaca sativa) Juice found in the leaves, stems, and fruits causes photosensitization.