Bergerocactus
| Bergerocactus | |
|---|---|
| File:Bergerocactus emoryi.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Pachycereeae |
| SubTribe | |
| Genus | Bergerocactus |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). |
Etymology
The genus is named in honor of Alwin Berger (1871–1931), a celebrated German botanist and curator of the Hanbury botanical garden at La Mortola, Italy.
Description
Bergerocactus is a monotypic genus consisting of large, spreading bushes with slender cylindrical stems that branch near the base. The plants are extremely spiny, covered almost entirely by golden-yellow aciculate (needle-like) spines that hide the epidermis. It has a robust and thick root system.
The flowers are diurnal and self-sterile. They feature a felted and spiny floral tube, are yellow in color, and often have reddish external petals. Pollination is primarily carried out by bees. The fruits are spherical, homochromous (the same color as the stems), and densely covered in spines, making them blend in with the rest of the plant. When ripe, the fruits dehisce at the apex to release a liquid pulp and seeds. The seeds are shiny, flattened, and brownish-black; their dispersal is likely ornithophilous (by birds).
Habitat
The genus grows in coastal areas along the Pacific, specifically in southwest California (USA) and northwest Baja California (Mexico). It is a key member of the "chaparral" plant community, consisting of thorny shrubs and other succulents. It is typically found from sea level up to approximately 250 m in altitude, growing in full sun.
Distribution
- Mexico (Baja California)
- USA (California)
Species
The genus contains only one recognized species:
Notes
- Historically, Bergerocactus was associated with Echinocereus due to its spiny fruits, but molecular studies (Wallace 1997, Arias et al. 2005) have shown it is closer to the Pachycereus and Peniocereus lineages.
- Anatomically, it is unique for possessing tannins in its epidermal cells and phloem fibers in cortical bundles.
- Despite its distinctness, it is known to form natural hybrids with other genera:
- ×Pachgerocereus orcuttii (hybrid with Pachycereus pringleii)
- ×Myrtgerocactus lindsayi (hybrid with Myrtillocactus cochal)
- Recent molecular work by Bàrcenas et al. (2011) suggests a distant link to Cephalocereus and a closer relationship to the Peniocereus/Acanthocereus clade.
