Astrophytum myriostigma var. nudum, commonly known as the "Bishop's Cap Cactus," is a spineless cactus with a smooth, spherical to cylindrical stem. Unlike the typical Astrophytum myriostigma, this variety lacks the white, hairy scales on its surface, giving it a sleek, green appearance. It typically has five ribs, though the number can vary between three and eight.
This cactus is admired for its geometric beauty and ease of care. It produces pale yellow, silk-like flowers in spring or early summer, but it can take up to six years to bloom for the first time. It thrives in well-draining soil, requires minimal watering, and prefers bright, indirect sunlight. It's also cold-hardy to about 20°F