Tiny globular bodies are densely covered with interlaced white radial spines, giving the impression of white "thimbles". Clusters prolifically to form large mats. Satiny creamy yellow flowers in late winter. Requires porous cactus soil. Prefers bright light with ample airflow. Water thoroughly when soil is dry to the touch. Cold tolerance to 25 degrees Fahrenheit, however, best to provide protection from frost to prevent scarring.