The name of this Genus is derived from the Latin "ferus" for fierce, because of its viscious spines.

(chin Cactus) There are 35 known species of this South American Genus. Characterized by short, curved spines, somewhat globular in shape, free flowering. The name of this Genus is derived from the Greek "gymnos" for bare, and "kalyx" for bud, since the flower buds are bare.

Native to the provinces of Negro and Chubut in Southern Argentina. Recognizable by its spherical, dark green stem, to 60 cm high. This plant has sunken areoles with 7 - 10 tough, pale brown, radial spines. Prominent, irregualarly shaped tubercles divided by deep grooves, 12 - 19 ribs. The 6 to 7 cm long flowers are white to pink and are quite large in proportion to the size of the Cactus. First described in 1812.

Needs a hot summer and while able to tolerate cold, it needs a frost-free winter. Propagate by seed or shoots.

A species that usually grows in clumps. Native to Argentina and Uruguay.

This species is named in dedication of William Harris, superintendant of Gardens and Plantations in Jamaica.

Reported to contain unspecified alkaloids.

The name of this genus is derived from the Greek word "yle" for forest.

The origin of this species is unknown, but it is semi-naturalised or cultivated in all tropical countries. Also known as Cereus triangularis. Plants known for their 3 slender, prominent ribs with corrugated edges. The 7 cm thick stems are long and climbing, thickly ramified. Areoles are far apart, each with 1 to 3 short spines. White nocturnal flowers and edible red fruit.

Roots need support to cling to, and a lot of growing room. Requires a mild climate without severe cold spells. Can also be used as a grafting stock for more hard to grow species.

Named after the small town of Islaya, located in the foothills on the Pacific coast of Peru.

Native to the town of Mollendo in the Andes foothills of Southern Peru. A very slow growing species with a solitary stem and 17 ribs, grows to 13 cm high. Has close set areoles with white - gray felt, topped by 20 or more sharp, slender, radial spines. Golden flowers to 2 cm across, bearing globular, hairy red fruit. The flowers form in the middle of the felted apical tip of the plant, clinging to it long after the blossum has withered. This species can also be classified as Noeporteria islayensis.