Although Pereskia does not resemble other cacti in its overall morphology, close examination shows spines developing from areoles, and the distinctive floral cup of the cactus family.

They are shrubs, trees or climbing vines, with maximum heights varying between 3 and 10 m. Unlike the great majority of species of cacti, they have persistent leaves.

[1][2][3] It is likely that Charles Plumier collected the first Pereskia specimens from the West Indies in the late 17th century.

Linnaeus did not accept Plumier's genus, placing the two species in Cactus, as C. pereskia and C. portacifolius.

The Bayesian consensus cladogram from this study is shown below with more recent generic assignments added.

[6][3] Species of Clade A always lack two key features of the stem present in most of the remaining "caulocacti": like most non-cacti, their stems begin to form bark early in the plant's life, and they also lack stomata – structures which control the admission of air into a plant and hence control photosynthesis.

The Andean clade consists of climbers or undershrubs with smaller flowers and does not form brachyblasts.

It has been introduced into several other parts of the world, including Mexico and the United States, South Africa, China and Australia.