African Rue originated in North Africa and in the deserts of Asia where it was used in the production of red dye. It was first recognized as an invasive species near Deming, New Mexico in the 1920s. The plant is highly toxic to both humans and animals if eaten, although dehulled seeds do produce edible oil that is very similar to cottonseed oil.
African Rue can be recognized by its numerous dense, branching stems, which are bright green, smooth, and fleshy, like its leaves. In the spring and summer, it produces small, five-petaled white flowers that grow at leaf axils along the stem. When crushed, the plant has a bitter acrid taste and emits a very unpleasant odor.
African Rue is extremely tolerant of drought and can grow in many types of soil, including alkaline and saline soils. With a taproot that has many branches and can grow to depths of 20 feet or more to follow water, the plant can spread rapidly into disturbed areas, such as roadsides and desertified rangelands. Each plant can produce as many as 1,000 fruits, with each fruit containing 40 – 50 seeds. During the summer, the plant dies back to its base. During the fall when the temperature is cooler and there is more moisture available, the plant regrows. It is thought that the regrowth period is mainly for the plant to store carbohydrates for its dormant months.