Kroenleinia
| Kroenleinia | |
|---|---|
| File:Kroenleinia grusonii.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Cacteae |
| SubTribe | |
| Genus | Kroenleinia |
| Species | |
| Notes | Taxonomy follows Joël Lodé (2015). Lodé separated this genus from Echinocactus based on DNA studies showing a closer relationship to Ferocactus. |
Etymology
The genus is named in honor of Marcel Kroenlein (1928–1994), who was the director of the Jardin Exotique de Monaco for 25 years.
Description
Kroenleinia is a monotypic genus containing the world-famous "Golden Barrel Cactus."
- Stems: Solitary, globose to shortly cylindrical with age, reaching up to 1 meter in diameter and height. The apex is covered with dense yellowish wool.
- Ribs: Numerous (up to 35 in mature plants), thin, and acute.
- Spines: Very prominent, stiff, and slightly curved. They are typically brilliant golden-yellow (hence the name), though white-spined forms exist in cultivation.
- Flowers: Diurnal, relatively small compared to the plant size, appearing in a ring around the woolly apex. They are vivid yellow and emerge only on mature specimens (usually over 20-30 years old).
- Fruits: Small, ovoid, and covered with white wool and scales. They become dry at maturity.
- Seeds: Small, dark brown to black, and shiny.
Habitat
The genus is endemic to central Mexico, growing on volcanic slopes and cliffs. Despite being one of the most common cacti in cultivation, it is considered Endangered in the wild due to habitat destruction (notably the construction of the Zimapán Dam).
Distribution
- Mexico: States of Querétaro and Hidalgo (specifically the Moctezuma River canyon).
Species
Following the 2014 reclassification by Lodé, the genus consists of only one species:
- Kroenleinia grusonii (Type species)
Taxonomy
Previously known as Echinocactus grusonii, molecular phylogenetics (Vázquez-Sánchez et al., 2013) demonstrated that it belongs to the "Ferocactus clade." Lodé established the genus Kroenleinia to accommodate this species, as it lacks the specialized fruit and seed characteristics of true Echinocactus.
