The oil in the plant causes the leaves to be very shiny. That means that each leaf has the appearance of 3 leaves. The oil in the plant causes the leaves to be very shiny. In winter and early spring look for clumps of light brown or grayish stems, usually to 5' tall with a strong upright habit. Sometimes, when it grows next to a tree and the exposure is favorable, it can climb to 20' or more by using the tree for support.
Older plants tend to branch but clumps of younger plants are usually made up of singular stems.
The berries hang on through early winter with only the stems remaining by spring. Various tribes used Poison Oak for a variety of things. They fashioned baskets from the roots and stems. They ground the roots for a coarse bread meal. Parts of the plant were boiled down to produce a black dye.