The tiny flowers are in 4 inch (10 cm) long, spike-like racemes. The edible seed pods are tan-colored, elongated, flat, and about 6 inches (15 cm) long. The leaves are bipinnately compound with 15 to 30 pairs of oblong, green, secondary leaflets. The bark on this desert tree is dark brown and very rough.

Velvet mesquite has a massive root system which can grow down as far as 50 feet to reach the water table. The taproot can be as big around as the trunk itself.

Mesquite, along with desert ironwoods are considered to be "nurse trees" to other desert plants like the saguaro, organ pipe cactus, and may succulents and forbs. Its nitrogen-rich soil feeds young seedlings while the canopy provides shelter and shade. Its foliage provides cover for large animals like javelinas and mule deer as well. Many species of rodents dig their burrows under the mesquite tree. The temperature under the tree can be 15° F cooler than the surrounding desert.