Fishhook cactus

Fishhook cactus is a common name for any hook-spined species of the genera Mammillaria, Echinomastus or Sclerocactus. They are small cacti, usually growing up to 6-7 inches (20 cm) high, and are shaped similar to a barrel cactus. They are not to be confused with the fishhook barrel cactus (Ferocactus wislizenii) of the Sonoran and Chihuahuan Deserts.

Good places to see "fishhook" Mammillaria are the Sonoran Desert on the U.S. - Mexico border, and the Mesa Verde National Park.