Mammillaria nejapensis, native to Oaxaca, Mexico, forms globular stems with silvery white spines up to 2" in length, and dense wool at the areoles. Becomes slightly columnar to 6" in height, branching dichotomously (each single stem begins to divide to form two stems) to form large clusters. Related to Mammillaria karwinskiana. Flowers are pale yellow with reddish midstripe on each petal. Requires excellent drainage from porous cactus soil. Prefers bright light with ample airflow. Water thoroughly when soil is dry to the touch. Protect from frost.