is most widespread in central and south Texas, from Austin southwards, and is also found in other coastal regions along the Gulf of Mexico states. Further west, the plant is native to southern Arizona, and has been introduced in other areas, including southern California, and around Las Vegas in Nevada. In some places it is considered an invasive weed.
Plants are shrubs or trees, with grey, often ridged stems bearing spines at the leaf nodes, one inch or more in length. Leaves are twice pinnate; between two and six pairs of primary leaflets, non-overlapping, each with up to 20 pairs of secondary, oblong leaflets. Leaves are attached by stalks of around half an inch.
The inflorescence is a spherical cluster, one to three per node, on shorter stalks than the leaves, Flowers are tubular, orange-yellow, with four or five sepals and the same number of petals. Fruits are slender pods, slightly flattened, green maturing to dark brown.