What Is a Tuna Plant?

Scientific Classification

• The tuna plant belongs to the Cactaceae, or Cactus family, as well as the subfamily Opuntia. Cactaceae includes up to 200 genera and thousands of species of plants that grow primarily in hot and dry regions. More than 30 distinct species belonging to the Opuntia family grow in the United States. Plants in the Cactaceae family develop long, shallow roots to help absorb rainfall and thin, sharp spines that protect the plant from predators. The thick fleshy stems of the tuna plant, like other cacti, store water absorbed by the roots.

Growing Tuna Plant

• Tuna plants grow up to 10 feet tall and 10 feet wide in dry sandy or rocky soil. Plants grown from seed require shade when young, but the adult plants thrive in full sun. Yellow, orange, pink or red flowers typically develop in the spring and produce harvestable fruit by August. The tuna plant can reproduce asexually by rooting one of the broad fleshy stems.

Predators

• The tuna plant possesses sharp spines to protect itself from predators intent on devouring stems and fruit as a source of water and vital nutrients. Cochineal insects and cactus beetles can infest and damage tuna plants. Birds feed on the fruit in the late summer. In the 1920s, Australians used the Cactoblastus cactorum, a moth, to kill an overgrowth of invasive tuna plants.

Uses

• People farm the tuna plant for its stems and fruit, or cultivate a row of the succulents to create a living fence. If planted approximately 1 foot apart, the tuna plants grow over several years to form a wall of spiny green stems. Traditional medicinal uses include applying the sap on the skin to soothe wounds and repel mosquitoes. Pureed leaves provide additional strength to buildings, dried leaf fibers offer a strong material from which to weave baskets, while the fresh pads can supplement the diets of livestock and poultry. Mexican cuisine uses tuna plant seeds to flavor soups and uses the leaves in salads, or serves them boiled, fried or pickled.