any species of the genus Coryphantha, family Cactaceae, and the straight-spined species of the genus Mammillaria.

Coryphantha (about 60 species) is native to western North America and central Mexico, with one species in Cuba. Globose to cylindroid, with protuberances not connected into ribs, species range in size from C. minima of Texas, about 5 cm (2 inches) in height, to Mexican species such as C. calipensis, which reach about 60 cm (24 inches) in length and 8 cm (3 inches) in diameter. A groove on the top of the tubercle, connecting the spine and flower-bearing parts, is characteristic of the genus and distinguishes it from Mammillaria.

C. vivipara (including its varieties) is almost as cold-resistant as the hardy prickly pears. It ranges from Alberta and Manitoba, in Canada, to Oklahoma and California, in the United States. C. missouriensis is also cold-resistant.

Coryphantha species have large flowers for the size of the plant. They are in shades of lavender, rose purple, pink, orange, yellow, and white. Fruits of the genus are green, red, or yellowish edible berries.

Neobesseya and Escobaria are usually considered subgenera of Coryphantha.