Opuntia macrorhiza aka Western Prickly Pear

Opuntia macrorhiza is a cactus known as plains prickly pear. Its native range covers the central and southern United States. It also reaches northern Mexico. It grows in dry plains, grasslands, and woods. This evergreen succulent forms low clumps with large, tuberous roots. Its species name refers to those roots. Growth is slow, and the plant needs little upkeep.

Garden plants stand about 0.5–1 foot (0.15–0.3 m) tall. Some accounts place their height below 0.8 feet (0.25 m). Reported widths differ, from 0.5–1 foot (0.15–0.3 m) for small clumps. Established mats can reach 3–5 feet (0.9–1.5 m) across. The thick pads are stems, not leaves. They have round or oval shapes and green to blue-green tones. Pads store water and wrinkle during drought. Spines grow in groups from small points called areoles. Tiny barbed bristles, called glochids, also cover the pads. Detached pads can root nearby and build a colony.

The flowers are yellow with red or orange near their centres. Each bloom measures about 0.17–0.25 feet (0.05–0.08 m) across. NC State lists flowering from June through July. Chicago Botanic Garden gives a wider window, from May through August. The flowers draw pollinators, including several skipper butterflies. Fleshy red-purple fruits ripen in late summer and fall. They reach about 0.08–0.13 feet (0.025–0.038 m) long. Their surface can carry glochids even when it lacks larger spines.

Grow this cactus in full sun with soil that drains well. It favours dry sand, gravel, or rocky ground. Clay can suit it if water drains away. NC State notes a preference for slightly acidic soil. The plant tolerates drought and suits USDA zones 3–9. Use it in rock gardens, containers, or small ground-cover patches. It can help hold sandy and rocky slopes. Its low mats also suit dry prairie and pollinator gardens. Leave space for new pads to root. Stem cuttings offer a simple way to grow more plants. Seed growing takes more effort.

Serious pests and diseases are uncommon, though scale and mealybugs can occur. Wet soil or poor drainage can lead to root rot. Deer and rabbits tend to avoid the plant. People eat the fruit fresh, cooked, or dried. They also roast the pads as a vegetable. Remove all spines and glochids before preparing either part. The bristles lodge in skin and can cause painful irritation. Some people develop a strong skin reaction after contact. Wear protective gloves when handling the plant.