Cultivation: They require an exposure in full sunny and well-ventilated environment with a minimum temperature of 6-7 ° C. Watering frequency: normal.
Curiosity: The name of this family of plants means, literally, “chalice with thorns” (from Greek ákantha, thorns, and cályx, chalice). The slivers on the floral tube and on the ovary are in fact changed in thorns.
ACANTHOCALYCIUM KEY FEATURES
Originally from the humid warmth of the Andes and the Pampas, the plants of the genus Acanthocalycium are decorative species that are appreciated either for the beauty of their colors and for the abundant blooms. The plants have round or cylindrical shape as long as they are young. They become more elongated as they grow, moving from almost perfect spheres to more elliptical shapes. Along the stem there are numerous ribs, up to 19-20 on adult plants, with large spiny and fluffy areolas that help us to distinguish them from other cacti.
They are of a greenish-gray color with nuances tending towards the yellow. The thorns are darker at the base and tend to be silver on the tip. When the plant is young the color is more lively and marked. The beauty of these plants, however, has to do with the great flowers that it produces in abundance. The flowering begins in spring and continues throughout the summer: on the top of the Acanthocalycium it is easy to notice squamous floral tubes (the “spiny chalices” that give them the name) from which large bellflower blooms with lively colors, generally yellow or red, or delicate tones that blend from pink to purple – according to the variety chosen. Only the plants with more than three years produce flowers – this is the time they need to reach full maturity.
VARIETIES AND TYPES
The genus Acanthocalycium was originally described in 1935 by Curt Backeberg, who had identified twelve different species: Acanthocalycium aurantiacum, brevispinum, catamarcense, chionanthum, glaucum, griseum, klimpelianum, peitscherianum, spiniflorum, thionanthum, variflorum and violaceum. Over the years, however, many of these have been reclassified under the Echinopsis and Lobivia genes, so that only three species are officially recognized as Acanthocalycium today
- A. Aurantiacum
- A. Brevispinus Hybrid
- A. Ferrari
- A. Glaucum
- A. Griseum
- A. Knippellianus
- A. Minutum
- A. Spiniflorum
- A. Thionanthum
- A. Violaciflorum
Since the classification of these species is still ongoing, it is easy to find different classifications (some still report, for example, the Glaucum under the Acanthocalycium genus, while others do not even include Ferrari). There are even more extreme positions: some botanists, in particular, consider all kinds of Acanthocalycium as a subgenre of Echinopsis.
TIPS FOR CULTIVATION
Are basically robust species, but they still need some cares and a suitable environment for them. These are the main indications for cultivating healthy specimens and good flowerings:
- A position in the sun, or very bright.
- An airy environment.
- A temperature never below 6 ° C. In winter it is therefore necessary to place them in a sheltered environment.
- Abundant watering in summer, indicatively every three, four days. In the winter, however, you can proceed with one weekly watering. In any case, be sure the soil is completely dry before proceeding with the next watering.
- A mixture of normal but well drained soil. Proceed with abundant fertilizers at least once a month months from May to October.
- The plants remain small in size (up to 15-20 cm in height for 10-15 cm in diameter) and therefore there is usually no need for repotting.
- Various species of Acanthocalycium reproduce by seed, which must be used fresh and placed in a wet soil. The optimum temperature for seed germination is the one of a temperate environment about 18-27 ° C.