About Mammillaria gigantea Hildm. ex K.Schum.
Mammillaria gigantea Hildm. ex K.Schum. is a low-growing, nearly cake-shaped cactus, often slightly sunken at the top, and covered in white wool felt. Its blue-green body reaches 9 to 10 cm (3.5 to 3.9 in) in height and 15 to 17 cm (5.9 to 6.7 in) in diameter. It has densely packed warts that produce milky juice, and its axillae are covered with white wool. This cactus has up to 12 small, straight, fine white needle-like radial spines, each up to 3 mm (0.12 in) long. It also bears 4 to 6 strong, usually curved central spines; the lowest of these can grow up to 2 cm (0.79 in) long. New central spines are yellow-brown with dark tips, and over time they fade to yellowish, white, or horn-colored, with a reddish base. Like all Mammillaria species, its flowers grow in a wreath formation. The flowers are green-yellow and measure about 15 mm (0.59 in) in diameter. The fruits are pink to greenish, and the seeds are brown. Mammillaria gigantea occurs in mountainous regions of the Mexican states of Guanajuato, Durango, San Luis Potosí, and Querétaro, growing at altitudes between 1,750 and 2,400 m (5,740 and 7,870 ft).
