Astrophytum ornatum - Monk's Hood Cactus

Monk's Hood Cactus is a shortly columnar cactus appearing star-shaped from above, with white cross bands of wooly scales. It appears to be a very variable species especially for the density and distribution of white scales. It is the largest and easiest to grow and also the fastest of the Astrophytums. It is also generally more heavily spined than other Astrophytums. The stem is solitary, globose when young , cylindric with age, 1-4 ft high, 15-30 cm across, greyish-green to dark-green with more or less dense white or yellow wooly flakes in bands forming an ornate pattern. It has 5 to 10 (generally 8) straight or frequently spiralling, rather prominent, strongly compressed, more or less sinuate and crenate . Areoles are 1 to 5 cm apart, at first yellowish-white felted, later grabrescent. Radial spines are 5-11, stout, 2-4 cm long usually straight, subulated or ± laterally compressed, amber yellow, later brown and finally grey. Flowers appear at the top, large, lemon-yelllow 7-12 cm broad, inner perianth segments broadly oblong, with a broad, more or less serrated apex, tube short woolly, scale on ovary, dark and very narrow.