''Pereskia'' is a small genus of about four

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

cacti A cactus (: cacti, cactuses, or less commonly, cactus) is a member of the plant family Cactaceae (), a family of the order Caryophyllales comprising about 127 genera with some 1,750 known species. The word ''cactus'' derives, through Latin, ...

that do not look much like other types of cacti, having substantial

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

and non-

succulent In botany, succulent plants, also known as succulents, are plants with parts that are thickened, fleshy, and engorged, usually to retain water in arid climates or soil conditions. The word ''succulent'' comes from the Latin word ''sucus'', meani ...

stems. The genus is named after

Nicolas-Claude Fabri de Peiresc Nicolas-Claude Fabri de Peiresc (1 December 1580 – 24 June 1637), often known simply as Peiresc, or by the Latin form of his name, Peirescius, was a French astronomer, antiquary and savant, who maintained a wide correspondence with scienti ...

, a 16th-century French botanist. The genus was more widely

circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...

until

molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...

studies showed that it was

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

. The majority of species have since been transferred to '' Leuenbergeria'' and '' Rhodocactus''. Although ''Pereskia'' does not resemble other cacti in its overall morphology, close examination shows spines developing from

areole In botany, areoles are small light- to dark-colored bumps on cactus, cacti out of which grow clusters of Thorns, spines, and prickles, spines. Areoles are important diagnostic features of cactus, cacti, and identify them as a family distinct fr ...

s, and the distinctive floral cup of the cactus family.

Description

The four species of ''Pereskia'' as the genus is now circumscribed share many features in common with ''Leuenbergeria'' and ''Rhodocactus'', which were formerly included in a broadly defined ''Pereskia''. 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. Like all cacti, they have spines borne on

s. Their succulent leaves are longer than wide, reaching 11 cm by 5 cm in the case of ''P. aculeata''. Their flowers are borne in small clusters or are solitary, except for ''P. aculeata'' which can have

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s of 70 or more individual flowers. ''P. aculeata'' has edible fruits, 1.5–2.5 cm in diameter; the other species have smaller fruits, only up to 6 mm in diameter in the case of ''P. horrida''. Unlike ''Leuenbergeria'', the stems of ''Pereskia'' delay forming bark and have

stoma In botany, a stoma (: stomata, from Greek language, Greek ''στόμα'', "mouth"), also called a stomate (: stomates), is a pore found in the Epidermis (botany), epidermis of leaves, stems, and other organs, that controls the rate of gas exc ...

ta. Unlike ''Rhodocactus'', there are no leaves on the areoles.

Taxonomy

It is likely that

Charles Plumier Charles Plumier (; 20 April 1646 – 20 November 1704) was a French botanist after whom the frangipani genus '' Plumeria'' is named. Plumier is considered one of the most important of the botanical explorers of his time. He made three botanizing ...

collected the first ''Pereskia'' specimens from the

West Indies The West Indies is an island subregion of the Americas, surrounded by the Atlantic Ocean, North Atlantic Ocean and the Caribbean Sea, which comprises 13 independent island country, island countries and 19 dependent territory, dependencies in thr ...

in the late 17th century. Plumier described two species of ''Pereskia'' in 1703.

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

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

Philip Miller Philip Miller Royal Society, FRS (1691 – 18 December 1771) was an English botany, botanist and gardener of Scottish descent. Miller was chief gardener at the Chelsea Physic Garden for nearly 50 years from 1722, and wrote the highly popular ...

published ''Pereskia'' in 1754, and as pre-Linnaean names are not accepted under the

International Code of Nomenclature for algae, fungi, and plants The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN or ICNafp) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all tho ...

, Miller rather than Plumier is credited as the author.

Phylogeny and evolution

A 2005 study suggested that the genus ''Pereskia'' as then

(''Pereskia'' ''

sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...

'') was basal within the Cactaceae, and confirmed earlier suggestions that it was

, i.e. did not include all the descendants of a common ancestor. The

Bayesian Thomas Bayes ( ; c. 1701 – 1761) was an English statistician, philosopher, and Presbyterian minister. Bayesian ( or ) may be either any of a range of concepts and approaches that relate to statistical methods based on Bayes' theorem Bayes ...

consensus

cladogram A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...

from this study is shown below with more recent generic assignments added. ''Pereskia'' ''s.l.'' divided into two main clades which differed in their geographical distribution. Clade A, the Northern

clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

, comprised species mainly found around the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

and the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

. Clade B comprised species found mainly in

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a considerably smaller portion in the Northern Hemisphere. It can also be described as the southern Subregion#Americas, subregion o ...

south of the

Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributary, tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries ...

, either in the

Andes The Andes ( ), Andes Mountains or Andean Mountain Range (; ) are the List of longest mountain chains on Earth, longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range ...

(the Andean clade) or further south (the southern South American or SSA clade). Subsequent studies confirmed the division of ''Pereskia'' ''s.l.'' into these three clades. 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 Bark may refer to: Common meanings * Bark (botany), an outer layer of a woody plant such as a tree or stick * Bark (sound), a vocalization of some animals (which is commonly the dog) Arts and entertainment * ''Bark'' (Jefferson Airplane album), ...

early in the plant's life, and they also lack

ta – structures which control the admission of air into a plant and hence control

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

. By contrast, species of Clade B typically delay forming bark and have stomata on their stems, thus giving the stem the potential to become a major organ for photosynthesis. The subclades of Clade B, the Andean and SSA clades, also show consistent differences. The SSA clade is distinctly tree-like with pink flowers and leaves as well as spines on its areoles, which can grow out to form short, densely crowded branchlets or brachyblasts, which produce leaves. The Andean clade consists of climbers or undershrubs with smaller flowers and does not form brachyblasts. In 2013, it was suggested that two distinct genera should be recognized, Clade A becoming '' Leuenbergeria'' and Clade B becoming a more tightly circumscribed ''Pereskia'' ''

sensu stricto ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...

''. In 2016, a further division of Clade B into two genera was proposed, with the Andean clade becoming a reduced ''Pereskia'' ''s.s.'' and the southern South American clade becoming the restored genus '' Rhodocactus''. ,

Plants of the World Online Plants of the World Online (POWO) is an online taxonomic database published by the Royal Botanic Gardens, Kew. History Following the Convention on Biological Diversity, the Royal Botanic Gardens in Kew launched Plants of the World Online i ...

accepts all three genera.

Species

, Plants of the World Online places four species in ''Pereskia'' ''s.s.'': Former species placed in ''Leuenbergeria'' are: *''Pereskia aureiflora'' F.Ritter = '' Leuenbergeria aureiflora'' (F. Ritter) Lodé *''Pereskia bleo'' (Kunth) DC = '' Leuenbergeria bleo'' (Kunth) Lodé *''Pereskia guamacho'' F.A.C.Weber = '' Leuenbergeria guamacho'' (F.A.C. Weber) Lodé *''Pereskia lychnidiflora'' DC = '' Leuenbergeria lychnidiflora'' (DC.) Lodé *''Pereskia marcanoi'' Areces = '' Leuenbergeria marcanoi'' (Areces) Lodé *''Pereskia portulacifolia'' (L.) DC = '' Leuenbergeria portulacifolia'' (L.) Lodé *''Pereskia quisqueyana'' Alain = '' Leuenbergeria quisqueyana'' (Alain) Lodé *''Pereskia zinniiflora'' DC = '' Leuenbergeria zinniiflora'' (DC.) Lodé Former species placed in ''Rhodocactus'' are: *''Pereskia bahiensis'' Gürke = '' Rhodocactus bahiensis'' (Gürke) I.Asai & K.Miyata *''Pereskia grandifolia'' Haw. = '' Rhodocactus grandifolius'' (Haw.) F.M.Knuth *''Pereskia nemorosa'' Rojas Acosta = '' Rhodocactus nemorosus'' (Rojas Acosta) I.Asai & K.Miyata *''Pereskia sacharosa'' Griseb. = '' Rhodocactus sacharosa'' (Griseb.) Backeb. *''Pereskia stenantha'' F.Ritter = '' Rhodocactus stenanthus'' (F.Ritter) I.Asai & K.Miyata

Synonyms

:''Pereskia colombiana'' = ''Leuenbergeria guamacho'' :''Pereskia corrugata'' = '' Leuenbergeria bleo'' :''Pereskia cubensis'' = ''Leuenbergeria zinniiflora'' :''Pereskia godseffiana'' = ''

Pereskia aculeata ''Pereskia aculeata'' is a scrambling shrub in the family Cactaceae. Common names include Barbados gooseberry, blade-apple cactus, leaf cactus, rose cactus, and lemonvine. It is native to tropical America. The leaves and fruits are edible, conta ...

'' :''Pereskia humboldtii'' = ''Pereskia horrida'' :''Pereskia philippi'' = '' Maihuenia poeppigii'' :''Pereskia subulata'' = ''

Austrocylindropuntia subulata ''Austrocylindropuntia subulata'' is a species of cactus native to the Peruvian Andes. The Latin specific epithet ''subulata'' means "awl-like", referring to the shape of the rudimentary leaves. It is also known by its common names as Eve's pin ...

'' :''Pereskia vargasii'' = ''Pereskia horrida'' :''Pereskia zehntneri'' = '' Quiabentia zehntneri'' :''Pereskia zinniaefolia'' = ''Leuenbergeria ziniiflora''

Distribution

The four species of ''Pereskia'' ''s.s.'' are almost entirely native to northern and eastern South America, excluding the

. ''Pereskia aculeata'' has the widest distribution, and is also found in

Panama Panama, officially the Republic of Panama, is a country in Latin America at the southern end of Central America, bordering South America. It is bordered by Costa Rica to the west, Colombia to the southeast, the Caribbean Sea to the north, and ...

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

Uses

The genus is not of great economic importance. ''Pereskia aculeata'' has edible fruit and is widely cultivated. The fruit contains numerous small seeds. It somewhat resembles a gooseberry in appearance and is of excellent flavor. This plant is a declared weed in South Africa. It can also be used as a

rootstock A rootstock is part of a plant, often an underground part, from which new above-ground growth can be produced. It could also be described as a stem with a well developed root system, to which a bud from another plant is grafted. It can refer to ...

for

grafting Grafting or graftage is a horticulture, horticultural technique whereby tissues of plants are joined so as to continue their growth together. The upper part of the combined plant is called the scion () while the lower part is called the roots ...

of ''

Schlumbergera ''Schlumbergera'' is a small genus of cactus, cacti with six to nine species found in the coastal mountains of south-eastern Brazil. These plants grow on trees or rocks in habitats that are generally shady with high humidity, and can be quite d ...

'' to create miniature trees.

References

Bibliography

* * *

External links

* * {{Authority control Pereskioideae Cacti of North America Cacti of South America Flora of the Caribbean Cactaceae genera Taxa named by Philip Miller