Mammillaria pilcayensis forms cylindrical columns to 15" in height. Very densely spined with whitish or golden spines nearly obscuring green body. Some forms have cinnamon-colored spines. Native to the mountains of Guerrero, Mexico. Profuse rings of bright majenta flowers appear in March and April. Closely related to Mammillaria spinosissima or "Red-headed Irishman". Requires porous cactus soil with adequate drainage. Bright light for best appearance. Water thoroughly when soil is dry to the touch. Protect from frost.