It grows in colonies that result from stems sprouting from roots. The bark is light brown and smooth on young plants. Twigs are stout, angular, smooth, and covered with a whitish coat that can be wiped off. Leaves are pinnately compound with 7-31 leaflets that are green on upper surface and nearly white on lower surface.
Leaves turn red in autumn.
The small, numerous flowers occur in much branched clusters. The fruit is a cluster of red drupes. Black walnut can be identified by slicing a stem to reveal a dark brown pith with air chambers. The pith of sumac is a lighter color and is homogenous, i.e. it lacks the air chambers. Winged sumac has wing-like tissue connecting the leaflets along the rachis of its compound leaf.