Cylindropuntia tunicata aka Sheathed Cholla

Cylindropuntia tunicata, or sheathed cholla, is a cactus. Its native range spans southwest Texas and parts of Mexico. It grows in deserts and dry scrub, including the Chihuahuan Desert. It lives on sand or gravel, often on lime-rich slopes. People and livestock have helped spread it beyond its native range. In several countries outside that range, it has become invasive.

This succulent shrub stores water and has many close-set branches. Its shape varies. Some plants hug the ground and form broad clumps. Others reach about 1.6–2 feet [0.5–0.6 metres], with a short, woody trunk. The green stems have joints that break off with ease. Some joints are almost round; others are narrow and oblong. Raised bumps called tubercles give each joint a rough surface. Yellow or tan wool coats the areoles, then turns grey with age. Most areoles bear five to twelve sharp spines. Thin, loose, paper-like sheaths cover the yellow to reddish spines. These sheaths range from white through yellow to tan. Dense spines can hide much of the green stem. Small tufts of pale yellow glochids grow at the areoles too.

Flowers open in late spring, with yellow to yellow-green tepals. Each flower spans about 0.1 feet [0.03 metres]. The fleshy fruits look like small tops or clubs. They turn yellow or yellow-green, at times with a red flush. Most lack spines, though some have a few weak ones. Most fruits are sterile. Broken-off joints can form small plants near the parent. Joints also catch on livestock, which take them to new sites.

This cactus grows in summer and needs soil that drains fast. Let the soil dry before you water it again. Cold and damp together raise the risk of root rot. LLIFLE lists USDA zones 7–10. It reports that the plant withstands frost near −7°C. Very dry plants may survive −12°C or lower. Yet LLIFLE advises frost-free care to avoid marks on the stems. Damp air makes frost more of a threat. The plant can also withstand strong summer heat.

Its dense, pale spines add structure to a cactus garden. LLIFLE says it is easy to grow when conditions suit it. Repot crowded roots in spring. Then give no water for at least a week. Raise new plants by stem division or with scarified seed. Scarifying means nicking or wearing down the seed coat. Sharp spines and glochids pose clear risks when handling this plant. The supplied sources do not establish food uses or chemical toxicity.