Blossfeldia
| Blossfeldia | |
|---|---|
| File:Blossfeldia liliputana.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Blossfeldieae |
| SubTribe | |
| Genus | Blossfeldia |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). |
Etymology
The genus was named in honor of Harry Blossfeld Junior (1913–1986), the German-Brazilian plantsman who discovered this taxon.
Description
Blossfeldia is famous for being the smallest of all known cacti. The plants are tiny, discoid, and button-shaped. They start as solitary specimens but eventually form small clumps. The epidermis is greyish-green and completely lacks spines.
The flowers are diurnal, subapical, and self-fertile, though they are also visited by bees. They are creamy-white to pale pink and feature a few tiny scales with scattered wool. The fruits are spherical, light brown or reddish, and dry when ripe, releasing a large quantity of tiny brown seeds. These seeds possess a wide aril and protuberances, which facilitate dispersal by ants (myrmecochory).
Habitat
The genus grows in northern Argentina and southern Bolivia at altitudes ranging from 1100 m to 3200 m. They are highly mimetic, growing in the cracks of schistose (shale) walls or steep rocky slopes. They often survive in pockets of humus or fine clay, forming colonies that cling to vertical rock faces.
Distribution
- Argentina (Catamarca, Jujuy, La Rioja, Mendoza, Salta, San Juan)
- Bolivia (Cochabamba, Chuquisaca, Potosí, Santa Cruz, Tarija)
Species
While many taxa have been described over the years, most botanists currently recognize only one extremely variable species:
Notes
- Blossfeldia is considered a "living fossil" in the cactus family. Molecular studies (Nyffeler 2002, Bàrcenas et al. 2011) place it in a basal position, as a sister group to all other members of the subfamily Cactoideae.
- The plant is uniquely adapted to extreme drought; it lacks a thick protective cuticle and possesses stomata only at the base of its areoles.
- It is a poikilohydric plant, meaning it can tolerate severe desiccation and recover upon rehydration, a trait more common in mosses and lichens than in cacti.
- Although it is currently treated as a single species, some variations in seed morphology suggest that there may be more than one taxon, pending further molecular analysis.
