Opuntia triacantha

Opuntia triacantha is a species of cactus known by the common names Spanish lady, Keys Joe-jumper, Big Pine Key prickly-pear, and jumping prickly apple. It is native to the Caribbean, from Desecheo Island, Puerto Rico, to the Lesser Antilles.

This cactus grows prostrate or upright to a maximum length of 60 centimeters. The stem segments are flattened and oval in shape, up to 18 centimeters long by 7 wide. The black-tipped spines are up to 4 centimeters long. The cactus produces yellow flowers year-round. The fleshy red fruit is up to 3 centimeters long by 2 wide.

The cactus grows on the sandy limestone of exposed reefs.

This species is threatened by the cactus moth (Cactoblastis cactorum).