Pierrebraunia
From M&J Cactus Wiki
| Pierrebraunia | |
|---|---|
| File:Pierrebraunia bahiensis.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Cereeae |
| SubTribe | Cereinae |
| Genus | Pierrebraunia |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). The genus is considered provisionally accepted but likely non-monophyletic. |
Etymology
The genus is named in honour of Pierre Josef Braun (1959–), German botanist and specialist of Brazilian cacti.
Description
Pierrebraunia is a small genus of usually solitary cacti, ranging from subglobose to elongated or weakly columnar forms.
- Habit: Solitary, sometimes weakly branched (P. brauniorum); erect or slightly bent.
- Stems: With 10–17 ribs (reduced to 4–5 in P. brauniorum); not constricted.
- Epidermis: Finely granular in P. brauniorum.
- Cephalium: Absent; flowering areoles may be woolly.
- Spines: Acicular, thin and fragile.
- Flowers: Diurnal, tubular, apical; pink to magenta; self-sterile; pollinated by hummingbirds.
- Fruits: Globose to ovoid, waxy; pale pink to wine-red; containing liquid pulp.
- Seeds: Black, matte; slightly striate and foveolate (smooth in P. brauniorum).
Habitat
The genus grows in dry, rocky environments:
- cliffs and steep slopes
- rock crevices and shallow soils
- open, sun-exposed habitats
Often associated with grasses, bromeliads, orchids, and other cacti.
Altitude range: около 1000 m.
Distribution
- Brazil:
* Bahia * Minas Gerais
Taxonomy
The genus Pierrebraunia was established in 1997 by Esteves Pereira.
Its taxonomic position is highly uncertain:
- Pierrebraunia bahiensis was previously placed in Floribunda and later in Arrojadoa
- It differs from Arrojadoa by lacking a cephalium, despite similar bird-pollinated flowers
- Molecular data suggest affinities with Lagenosocereus
Pierrebraunia brauniorum is even more problematic:
- possibly related to Pilosocereus
- or a natural hybrid involving Arrojadoa or Micranthocereus
These taxa may represent cases of reticulate evolution.
The genus is therefore considered artificial and probably non-monophyletic, but provisionally maintained.
Species
Following Joël Lodé (2015):
Notes
- The genus likely represents a temporary taxonomic solution.
- Both species may eventually be reassigned to other genera.
- Pollination shift (bat → hummingbird) is suggested in evolutionary scenarios.
- A good example of complex evolution in Brazilian cacti.
