The berries of poison sumac start out green in spring and remain that color for much of the summer. They grow in clusters. The poison sumac berry cluster is quite distinct from the berry cluster of nonpoisonous sumacs (Rhus typhina, for example), in terms of color, shape, and texture.
Learn the other attributes of the leaf. Poison sumac is deciduous, so the leaves change color throughout the year. Newly grown spring leaves may be bright orange, becoming light green during spring and summer, changing to red during autumn, then falling off the plant entirely.
Poison sumac has leaves made up of from 5 to 13 such leaflets. While the exact number varies, it is always an odd number. That's because, while most of the leaflets form matching pairs (one across from the other), there's always one lone leaflet at the tip of the compound leaf, which gives it the shape of a feather.