Austrocactus
| Austrocactus | |
|---|---|
| File:Austrocactus bertinii.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Phyllocacteae |
| SubTribe | Corryocactinae |
| Genus | Austrocactus |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). |
Etymology
The name Austrocactus means "Cactus of the South" or "Southern cactus", referring to the genus being found exclusively in the southern regions of South America (Patagonia).
Description
Austrocactus is a genus of small, low-growing plants that can be solitary or branching at the base. They are characterized by a slow growth rate and tender, fleshy stems. The stems feature low ribs divided into tubercles, with spines that can be either straight or hooked.
The flowers are diurnal, self-sterile, and appear subapically or laterally. They are bell-shaped and pollinated by bees. The fruits are spherical to oblong, exhibiting irregular or basal dehiscence (splitting), and the floral remains are persistent. The seeds are more or less ovate, tuberculate, and wrinkled.
Habitat
The genus grows in Patagonia, spanning both Chile and Argentina. It has a vast altitude range, from sea level up to 4000 m. These plants are very polymorphic and can be found in full sun or sheltered among bushes, typically growing on stony or sandy soils.
Distribution
- Argentina (Chubut, La Pampa, Mendoza, Neuquén, Río Negro, Santa Cruz)
- Chile (Maule, Santiago)
Species
According to the Joël Lodé index, there are currently 7 recognized species:
- Austrocactus bertinii (syn. A. patagonicus)
- Austrocactus coxii
- Austrocactus ferrari
- Austrocactus hibernus
- Austrocactus longicarpus
- Austrocactus philippii
- Austrocactus spiniflorus
Notes
- Historically placed in the tribe Notocacteae, modern phylogenetic data (Nyffeler, 2010; Hernández-Hernández, 2011) places Austrocactus in the subtribe Corryocactinae. It forms one of the most basal branches of this clade alongside Corryocactus and Eulychnia.
- The genus is known for being highly variable in shape, spines, and flowers, making identification difficult. Differences between habitat-grown and cultivated plants are often significant.
- There is ongoing taxonomic debate regarding species boundaries. For example, some experts consider A. gracilis and A. patagonicus as synonyms of A. bertinii.
- Some researchers, such as E. & N. Sarnes, suggest that A. spiniflorus might eventually be excluded from the genus due to its distinct morphological differences from other species.
