About Mammillaria grusonii Ruenge
Mammillaria grusonii typically grows as a single individual. This cactus has a shape ranging from spherical to thickly cylindrical, is bright green in color, and reaches approximately 25 centimeters (9.8 inches) in diameter. Its tubercles are four-angled and contain latex. The axillae are covered in wool when young, and become bare as the cactus matures. Its spines are straight, reddish when new, and turn white as the cactus ages. This species has two central spines that measure 0.4 to 0.6 centimeters long, and 12 to 14 radial spines that measure 0.6 to 0.8 centimeters long. It produces pale yellow, bell-shaped flowers that grow up to 2.5 centimeters long, with an equal diameter. The fruits are bright scarlet and hold brown seeds. This species is native to Mexico, where it occurs in the states of Coahuila and Durango, growing at altitudes between 800 and 1,850 metres (2,620 and 6,070 feet) above sea level.
