About Mammillaria rhodantha Link & Otto
Mammillaria rhodantha Link & Otto, commonly called the rainbow pincushion, is a small cactus. Its height typically ranges from 15 to 30 cm (6 to 12 inches). It usually forms small clumps, though it may also grow as a single solitary plant. Its stem is a short, hairless column covered in spines. The entire plant body is covered in conical tubercles, and spines grow from these tubercles. Each tubercle produces between 15 and 18 spines, which measure 3 to 7 mm (0.12 to 0.28 inches) in length. Spines grow across the full body of the cactus; spines on the bottom half of the plant are white or gray, and may appear to be dying. White wool can be seen growing on the upper portion of the plant body. This species flowers for a very long period: it typically begins blooming in spring and continues flowering until autumn. Its flowers are colored deep pink to purple. After flowering, the cactus produces orange-brown seeds. M. rhodantha has frost tolerance, and can survive temperatures as low as −4 °C (25 °F).
