Pereskia is a genus of about 25 tropical species and varieties of cacti that do not look much like other types of cacti, having substantial leaves and thin stems. They originate from the region between Brazil and Mexico. The genus is named after Nicolas-Claude Fabri de Peiresc, a 16th century French botanist, which also has been given its own subfamily Pereskioideae. Members of this genus are usually referred to as lemon vines, rose cacti or leaf cacti, though the latter also refers to the genus Epiphyllum.
Species of Pereskia generally resemble other types of plants, such as wild roses. Pereskia species have large, bright green, privet-like leaves and long spiny stems. Not always succulent plants, they can be classified as shrubs, climbing plants or slightly succulent trees. However, close examination shows spines developing from areoles, and the distinctive floral cup of the cactus family. Unlike Pereskiopsis, Maihuenia, Quiabentia and Austrocylindropuntia which have persistent succulent leaves, Pereskia is the only cactus genus that has persistent non-succulent leaves. It is believed that this is the origin of other cacti.
Shrub species usually grow to 1m in height, but climbing or arborescent species can reach 5 to 20 m. Flowers may appear alone or in clusters. They generally resemble roses and reach a diameter of 1 to 5 cm. Colors of the flower depend on each species and vary from white, yellow to magenta or red. Fruits are ordinarily spherical, of 2 to 5 cm diameter, and are wine red when ripe.
Most of the species are found in dry forests or thorny scrub, in tropical climates with a dry season of two to five months. They are found from southern Mexico to Colombia and Venezuela, and throughout the West Indies, as well as the eastern part of Brazil south to northern Uruguay and Argentina. Several types are native to the Andes in Peru and Bolivia, though not on the Pacific side. They have found in the US state of Florida, but are probably introductions rather than natives.
Most likely Charles Plumier collected the first Pereskia specimens from the West Indies between 1689 and 1695, but none of these have survived. Although Plumier described Pereskia in 1703, Linnaeus placed Plumier's two species in his Cactus, as 'C. pereskia and C. portacifolius. Philip Miller brought the original name back in 1754, and so by the rules of botanical nomenclature, he is credited as the author.
The genus Rhodocactus (A.Berger) F.M.Knuth has been brought into synonymy with this genus, as well as different orthographic variants: Peirescia Zucc. (orth. var.), Peireskia Steud. (orth. var.) and Perescia Lem. (orth. var.).
The genus is not of great economic importance, the most common usage being as hedges; they are easily transplanted and quickly grow into an impenetrable thicket, as well as flowering prolifically. Being more tolerant of moisture than more succulent cacti, they can be used as rootstock for grafting of Zygocactus to create miniature trees.