Mammillaria vetula subsp. gracilis, commonly known as Thimble Cactus, Arizona Snowcap, or Golden Stars, is an evergreen succulent native to the arid regions of Central and Northern Mexico, typically found in desert mountains on dry, rocky hillsides and outcroppings. It is a slow-growing plant, reaching heights of 0.3-0.5 feet (0.09-0.15 meters) and spreading 0.5-1 feet (0.15-0.3 meters). This cactus features cylindrical stems covered in white spines, giving it a snowy appearance, and it produces white or pink flowers that are quite showy when they bloom in the spring.

The Thimble Cactus is valued for its ease of care and the aesthetic appeal of its compact form and attractive spination. It is often used in rock gardens, as a container plant, or in succulent collections. It requires minimal water, thriving in fast-draining sandy soils, and prefers full sun to partial shade. While it is generally pest-resistant, overwatering can lead to root rot. It is not cold-hardy and should be protected from frost.CC BY-SA 4.0