This drought-tolerant shrub or small tree is Physic Nut, Jatropha curcas. It belongs to the spurge family, Euphorbiaceae, along with cassava, poinsettia, croton and Peregrina. Its precise original range is uncertain because people have moved and cultivated it for centuries, but it is generally associated with tropical America and is now widespread throughout the tropics.

Physic Nut usually grows as a many-branched shrub or small tree with a soft, somewhat succulent trunk. It grows quickly in warm climates and can survive long dry periods by shedding some or all of its leaves.

The leaves are large, smooth and broadly heart-shaped, often with three to five shallow lobes. They are carried on long stalks and may form a fairly open crown.

When a leaf or branch is broken, the plant releases a white, sticky latex. That sap may irritate the skin and is one sign that the plant belongs to the spurge family.

The flowers are small and usually greenish-yellow. Male and female flowers occur separately within the same branching cluster, with many more male flowers than female ones.

Bees, flies and other insects visit the flowers and assist with pollination. Afterward, the female flowers develop into rounded or oval fruits divided into three sections.

The fruits begin green and become yellow, brown or nearly black as they mature. When dry, they split apart and usually release three large, dark seeds.

Those seeds resemble small beans or nuts, but they are poisonous and must never be eaten. They contain irritating and toxic compounds that can cause severe vomiting, diarrhea and other serious illness.

The name “Physic Nut” comes from the plant’s long history in traditional medicine. The seed oil was once used as a powerful purgative, or “physic,” but its toxicity makes such use dangerous and inappropriate for self-treatment.

The seeds contain a high percentage of oil. That oil has been used for lamps, soap and industrial purposes and has received considerable attention as a possible source of biodiesel. It cannot simply be treated as an ordinary edible vegetable oil.

Physic Nut has also been planted as a living fence. Livestock often avoid its bitter, toxic foliage, while cut branches can root readily and form a dense boundary.

The tree tolerates heat, drought and poor soils, but claims that it can produce large quantities of fuel on completely barren land have often proved overly optimistic. Good seed production still depends on suitable soil, moisture and management.

This is therefore a plant with both practical value and genuine danger. Its oil-rich seeds can provide fuel and industrial products, but those same seeds contain powerful toxins.

When presenting it to a group, the most important features to point out are the broad, lobed leaves, the three-part fruits and the large seeds—with a clear warning that no part of the plant should be sampled.