Wigginsia erinaceus
Description:
Native to Brazil, Argentina, Uruguay. Globular cactus to 15 cm in diameter. Dark green, wooly at the top and with 15-20 broad spiral ribs; notched wooly areoles in the depressions, small brownish spines.
Loves the Gulf Coast climate including Houston. This cactus will flower profusely from the spring all through into late fall.