Pereskia
| Pereskia | |
|---|---|
| File:Pereskia aculeata.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Pereskioideae |
| Tribe | |
| SubTribe | |
| Genus | Pereskia |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). The genus is treated here in the strict sense (Pereskia sensu stricto). |
Etymology
The genus is named in honour of Nicolas-Claude Fabri de Peiresc (1580–1637), a French astronomer, botanist and naturalist.
Description
Pereskia is a genus of shrubby to tree-like cacti, representing one of the most basal lineages within the family.
- Habit: Much-branched shrubs or small trees, sometimes with tuberous roots.
- Stems: Cylindrical, non-segmented, non-ribbed, with persistent green epidermis and stomata.
- Leaves: Present, broad, weakly succulent or non-succulent, deciduous or subpersistent.
- Areoles: Often bearing numerous spines; glochids absent.
- Flowers: Diurnal, self-sterile, solitary or grouped in inflorescences; white, pink or red.
- Fruits: Berry-like or pear-shaped, fleshy, indehiscent.
- Seeds: Large, brown to black, rounded to kidney-shaped, shiny.
Habitat
The genus occurs in a wide range of habitats, including dry forests, shrublands, and rocky slopes, from sea level up to about 2180 m. Plants often grow in shaded environments and may resemble non-cactus shrubs when not in flower.
Distribution
- South America:
Argentina (Catamarca, Chaco, Formosa, Jujuy, Salta), Bolivia (Beni, Chuquisaca, Cochabamba, Santa Cruz, Tarija), Brazil (Bahia, Ceará, Espírito Santo, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Pernambuco, Rio de Janeiro, São Paulo), Paraguay (multiple departments), Peru (Amazonas, Cajamarca, La Libertad), Uruguay
- Introduced and naturalized in tropical regions (especially P. aculeata).
Taxonomy
The genus Pereskia was established by Miller (1754) and represents one of the earliest diverging lineages within the cactus family.
Molecular studies have shown that Pereskia is paraphyletic. Two major clades can be distinguished:
- a "Northern" clade (now separated as Leuenbergeria)
- a "Southern" clade, retained as Pereskia sensu stricto
According to Joël Lodé (2015), the genus Pereskia is maintained in a strict sense (s.s.), including only the southern species.
Species
Following the classification of Joël Lodé (2015).
- Pereskia aculeata
- Pereskia bahiensis
- Pereskia diaz-romeroana
- Pereskia grandifolia
- Pereskia horrida
- Pereskia nemorosa
- Pereskia sacharosa
- Pereskia stenantha
- Pereskia weberiana
Notes
- Pereskia is considered one of the most primitive cactus genera.
- The presence of true leaves distinguishes it from most other cacti.
- The genus is paraphyletic and likely to be further subdivided in future classifications.
