This perennial shrub puts out leaves in early spring, but they begin to drop within a month.
Flowers are a brilliant yellow, can be profuse, and appear in April and May. Seeds are encased in a long pod. Because the leaves of this plant are few, the plant actually uses the green stems to carry out the process of photosynthesis. Weak spines may be present.
Senna can be found in the open desert from about 600 to 3300 feet (200-1000 m) but is especially abundant along roadsides in disturbed areas.