This spherical to columnar cactus has 4-8 prominent ribs that are lined with light brown areoles. The green surface covered in minute woolly white scales and the diurnal yellow funnel-shape flowers appear in summer from the top centre of the plant.

Hardiness zones 10 to 11 

Astrophytum myriostigma is naturally found in the Highlands of northern and central Mexico growing at an altitude of over 2000 m (6563 feet) on dry-arid, rocky slopes. It prefers an open position, with some shade from hot mid-day sun and grows in sharply drained stony soils that are moderately fertile and tending alkaline and is drought tolerant but frost tender. 

Bishop's Cap is grown for its habit and flowers. It is grown in small or arid gardens and used in rockeries. It is also grown as a potted specimen plant, under glass in cold climates and is suitable for mountainous regions establishing in 3-4 years and is long lived. ID 2066

Astrophytum (ass-tro-FY-tum) myriostigma (MEE-ree-oh-STIG-mah)

Cactaceae (kak-TAY-see-ee)