Acanthocalycium thionanthum
| Acanthocalycium thionanthum | |
|---|---|
| |
| Kingdom | Plantae |
| Family | Cactaceae |
| Subfamily | Cactoideae |
| Tribe | Trichocereeae |
| SubTribe | |
| Genus | Acanthocalycium |
| Species | Acanthocalycium thionanthum |
| Notes | Taxonomy follows Joël Lodé (2015–2019), with alternative classifications noted below. |
Description
Acanthocalycium thionanthum is a small to medium-sized cactus species native to Argentina. Plants are usually solitary, globose to short cylindrical, dark green to gray-green, reaching up to 12 cm in height and 10 cm in diameter.
The ribs are 9–15, rounded and slightly notched. Areoles are elliptical. Spines are awl-shaped, gray with darker tips, typically 1–1.5 cm long. Central spines (1–4) may be absent, while radial spines number 5–10.
Flowers are somewhat bell-shaped and variable in color, ranging from bright yellow to red or white, up to 4.5 cm in length and diameter. Floral tubes bear dark, spine-tipped scales along with hairs and bristles. Fruits are globose, dry, and dehiscent, up to 1 cm in diameter.
Distribution
- Argentina – Salta Province
Taxonomy
According to Joël Lodé, this species is placed in the genus Acanthocalycium.
However, in broader phylogenetic classifications, it is often included within Echinopsis. The species has a complex taxonomic history with numerous synonyms across different genera.
Synonyms
The following names have been applied to this species:
- Echinopsis thionantha – (Spegazzini) Werdermann (1931)
- Echinocactus thionanthus – Spegazzini (1905)
- Lobivia thionantha – (Spegazzini) Britton & Rose (1922)
- Echinocactus chionanthus – Spegazzini (1905)
- Lobivia chionantha – (Spegazzini) Britton & Rose (1922)
- Echinopsis chionantha – (Spegazzini) Werdermann (1931)
- Acanthocalycium chionanthum – (Spegazzini) Backeberg (1935)
- Acanthocalycium brevispinum – F. Ritter (1964)
- Echinopsis brevispinum – (F. Ritter) H. Friedrich & G.D. Rowley (1974)
Invalid or doubtful names
- Acanthocalycium griseum – not validly published
- Acanthocalycium catamarcense – considered synonymous
Notes
- Species shows high variability in flower color and spine development.
- Frequently encountered under different generic names in horticulture.
- One of the more widely distributed species within the genus.
Cultivation
This species is relatively easy to cultivate:
- prefers well-draining mineral substrate
- requires bright light for compact growth
- tolerates cool temperatures if kept dry in winter
