Acanthocalycium glaucum
| Acanthocalycium glaucum | |
|---|---|
| File:Acanthocalycium glaucum.jpg | |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Trichocereeae |
| SubTribe | |
| Genus | Acanthocalycium |
| Species | Acanthocalycium glaucum |
| Notes | Taxonomy according to Joël Lodé (v1.19). |
Description
Acanthocalycium glaucum is a small, solitary cactus species characterized by its distinct glaucous (bluish-grey to silvery-green) epidermis. The stems are globose to short cylindrical, reaching up to 10-15 cm in height.
The ribs (typically 8–14) are well-defined and slightly tuberculate. Areoles are felted, bearing 5–10 radial spines that are straight, dark grey to blackish when young, later turning grey.
The flowers are a highlight of this species: funnel-shaped, typically bright yellow to orange-yellow, about 6 cm in diameter. The floral tube is covered with characteristic papery scales and white hairs, which gives the genus its name.
Distribution
- Argentina: Found primarily in the provinces of Catamarca and La Rioja, growing in rocky, mineral-rich soils at altitudes between 500 and 1000m.
Taxonomy
According to Joël Lodé (Taxonomy of the Cactaceae, 2015), Acanthocalycium glaucum is a distinct and accepted species. While some previous authors (like Hunt) treated it as a variety of Acanthocalycium thionanthum, molecular and morphological data supported by Lodé maintain its specific rank.
Synonyms
Based on the Lodé Index (v1.19), the following names are associated with this taxon:
- Acanthocalycium aurantiacum Rausch
- Acanthocalycium thionanthum var. glaucum (Ritter) Donald
- Echinopsis glaucina H.Friedrich & G.D.Rowley
- Lobivia thionantha var. glauca (Ritter) Rausch
Cultivation
This species is highly valued by collectors for its contrast between the blue skin and yellow flowers.
- Soil: Requires a strictly mineral, well-draining substrate.
- Watering: Regular during summer, but must be kept completely dry in winter to prevent root rot.
- Light: Needs full sun to maintain its glaucous wax coating and produce dense spines.
- Hardiness: Can tolerate brief frosts down to -5°C if dry.
