This oily substance is what causes a poison oak rash, and it can be almost impossible to avoid. Poison oak, like poison ivy, contains urushiol. Symptoms can take 24-48 hours or even up to a week to show up, particularly if its your first exposure! Symptoms of poison oak include itchy red rashes that can resemble burns, swelling, and even blistering. Right: Poison Oak leaflets showing coloration. Left: Poison Oak can be red in the fall, and its berries are tan when mature.
Leaf shape resembles an oak leaf (hence the name, poison oak), but it’s not a member of the oak family.It can grow to be about 3 feet tall, sometimes giving it the appearance of a vine. Poison oak is a low-growing, upright shrub.
poison oak (right) How to Identify Poison Oak In North America, there are two species of poison oak: Atlantic (Eastern) and Pacific (Western). Depending on the season, leaf color can range from green to orange and even a dark purplish-red.īut they are indeed different plants.Middle leaflet has a notably longer stem than the two side leaflets, though more obvious in poison ivy than poison oak.Leaflets can range in size from the length of your thumb to the length of your hand.Both plants have three leaflets, white flowers in spring, and can grow as a vine or a shrub.Both plants contain the same toxic resin, urushiol in all parts of the plant (toxic to humans but harmless to animals).ADVERTISEMENT What is the Difference Between Poison Oak and Poison Ivy?