A medium to large tree with a straight, tall trunk and narrow, rounded or pyramidal crown.
Leaves opposite, feather-compound, 8–12 inches long, with 5–9 (usually 7) leaflets; leaflets broadest near the base or middle, 3–5 inches long, 1½–3 inches wide, margin often with rounded teeth, tip pointed, upper surface dark green, dull to somewhat shiny; lower surface paler, whitish, smooth; leaf stalk smooth.
Bark light gray to dark brown, grooves deep, with narrow, interlacing ridges that are flat-topped, forming a diamond pattern.
Twigs stout, rigid, brittle, green to brown, or gray, smooth; pores pale; bud at tip about ¼ inch long.
Flowers April–May, with male and female flowers in clusters on different trees. Male flowers small, green to red, with no petals; female flowers similar to male flowers.
Fruit matures in August–September, in dense clusters up to 8 inches long; fruit is a samara, with the wing partially around the seed; yellowish-brown, 1–2 inches long, smooth, flat.