Poison-oak: Identifying Characteristics
Habitat:
This shade-intolerant species grows well in dry habitats.
Size/Form:
Shrub that reaches a maximum of 3' in height. This non-climbing plant has subterranean runners.
Leaves:
Leaves are alternate with multi-lobed leaflets (three leaflets per leaf). Although this plant is not related to the true oaks in the genus Quercus, the lobing on the leaflets makes the plant look oak-like. Leaflets are ovate to elliptic, growing up to 4" long, and up to 2 1/2" wide. Lobed or toothed margin. Leaves are a dull green and have hairs on both sides. Young twigs may be pubescent but older stems become glaborous. This plant contains toxic substances and skin contact with it can cause severe irritation to some people.
Fruit:
Drupes are spherical, smooth or lightly pubescent, and up to 1/3" in diameter. Older drupes have shallow longitudinal grooves.