Cnidoscolus aconitifolius

Cnidoscolus aconitifolius, commonly known as chaya or tree spinach, is a large, fast-growing leafy perennial shrub that is believed to have originated in the Yucatán Peninsula of Mexico. The specific epithet, aconitifolius, means "Aconitum-like leaves". It has succulent stems which exude a milky sap when cut. It can grow to be 6 meters tall, but is usually pruned to about 2 m for easier leaf harvest. It is a popular leaf vegetable in Mexican and Central American cuisines, similar to spinach. The leaves should be cooked before being eaten, as the raw leaves contain a high content of toxic hydrocyanic acid. Up to 5 raw leaves can be eaten a day. To be safely eaten, the required cooking time is 5-15 minutes.

Some varieties have stinging hairs and require gloves for harvesting. Cooking destroys the stinging hairs. Chaya is one of the most productive green vegetables.

Chaya is a good source of protein, vitamins, calcium, and iron; and is also a rich source of antioxidants. However, raw chaya leaves are toxic as they contain a glucoside that can release toxic cyanide. Cooking is essential prior to consumption to inactivate the toxic components; in this chaya is similar to cassava, which also contains toxic hydrocyanic glycosides and must be cooked before being eaten.

Young chaya leaves and the thick, tender stem tips are cut and boiled as a spinach. It is a tasty vegetable, and is exceptionally high in protein, calcium, iron, and vitamin A. In fact, levels of chaya leaf nutrients are two- to threefold greater than any other land-based leafy green vegetable. Chaya leaves have a possible antidiabetic effect.

Traditionally leaves are immersed and simmered for 20 minutes and then served with oil or butter. Cooking for 20 minutes or more will render the leaves safe to eat. The stock or liquid the leaves are cooked in can also safely be consumed as the cyanide is volatilized as hydrogen cyanide (HCN) during cooking. Cooking in aluminum cookware can result in a toxic broth, causing diarrhea.