Castellanosia
| Castellanosia | |
|---|---|
| File:Castellanosia caineana.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Phyllocacteae |
| SubTribe | Corryocactinae |
| Genus | Castellanosia |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). |
Etymology
The genus was named in honor of the Argentine botanist Alberto Castellanos (1896–1968).
Description
Castellanosia is a monotypic genus of treelike cacti that branch from the base. They are characterized by cylindrical stems that often show distinct constrictions. The vegetative (non-flowering) shoots typically have 9 ribs with grey areoles and brown spines. However, the flowering parts of the stems develop long, grey-to-brown bristles, which distinguish them from the vegetative growth.
The flowers are nocturnal, bell-shaped, and purple-red. They are covered in scales and felted hairs, specifically adapted for pollination by bats (Glossophaga soricina). The fruits are globose and greenish-yellow with a dark yellow pulp. Notably, historical records (Backeberg, 1976) describe the fruit pulp as exceptionally poisonous. The fruits retain the dried remains of the floral parts. The seeds are rough and range from reddish-brown to black, primarily dispersed by fruit-eating bats.
Habitat
The genus grows along the Rio Caine and in the southwestern Bolivian Chaco. It thrives on inclined slopes in dry valleys and woodlands, often at altitudes between 530 m and 2330 m. It is found in high-biodiversity areas alongside other cacti like Blossfeldia liliputana, Neoraimondia herzogiana, and various epiphytic Bromeliads. The presence of lichens in its habitat indicates periods of high humidity.
Distribution
- Bolivia (Cochabamba, Chuquisaca, Santa Cruz, Tarija)
- Paraguay (Alto Paraguay, Boquerón, Concepción)
Species
Currently, the genus is considered monospecific:
Notes
- Although previously included in Browningia or Neoraimondia, molecular studies (Applequist & Wallace, 2002; Hernández-Hernández et al., 2011) have shown that Castellanosia lacks certain genetic markers (like the rpl16 chloroplast intron) found in those genera, justifying its status as a distinct genus.
- It is placed within the tribe Phyllocacteae, subtribe Corryocactinae.
