Frailea
| Frailea | |
|---|---|
| File:Frailea castanea.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Notocacteae |
| SubTribe | |
| Genus | Frailea |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). Lodé maintains Frailea as a distinct genus within Notocacteae. |
Etymology
The genus is named in honor of Manuel Fraile (1850–?), who was in charge of the cactus collection at the Department of Agriculture in Washington, D.C.
Description
Frailea consists of tiny, usually globose to shortly cylindrical cacti, which are often short-lived in habitat.
- Stems: Small, often barely rising above the soil level, and frequently dark-colored (brownish or purplish).
- Flowers: Diurnal and often cleistogamous (pollinating themselves without opening). When they do open, they are relatively large, funnel-shaped, and usually sulfur-yellow.
- Fruits: Globose, dry, and covered with scales and bristles. They are indehiscent and characterized by a "papery" wall.
- Seeds: Relatively large for the size of the plant, helmet-shaped (hat-shaped), black or dark brown, and often floating to aid in dispersal by water.
Habitat
Frailea species grow in pampa grasslands, often on rocky outcrops, sandy soils, or among pebbles. They are found at low altitudes, from sea level up to 1000 m. They are highly adapted to survive periods of drought by shrinking into the ground.
Distribution
- South America: Argentina, Bolivia, Brazil (Rio Grande do Sul), Paraguay, and Uruguay.
Species
Following the strict assessment by Lodé (2015), the genus includes 19 species and 14 subspecies:
- Frailea buenekeri
- Frailea castanea
- Frailea cataphracta
- Frailea chiquitana
- Frailea curvispina
- Frailea friedrichii
- Frailea gracillima
- Frailea grahliana
- Frailea knippeliana
- Frailea mammifera
- Frailea perumbilicata
- Frailea phaeodisca
- Frailea pumila
- Frailea pygmaea
- Frailea schilinzkyana
- Frailea stockingeri
- Frailea uebelmanniana
- Frailea zapicanensis
Taxonomy
Frailea is closely related to Notocactus, but it is distinguished by its small size, cleistogamous flowers, and specific seed morphology. Lodé notes that many described names in the trade are merely synonyms or local forms of the highly variable F. pygmaea and F. pumila.
