Acanthocalicium chionanthum P67 Portrero 2500m,
This is a very variable species, with several forms and varieties.
Description: Usually solitary or slowly branching through basal
shoots, but quite variable taxon with several forms.
There are a number of varieties of this highly variable cactus species,
but not all are universally recognized.
Stem: Spherical, over time it becomes slightly cylindrical,
growing to a height of 12 cm or more, and a diameter of 6 to 10 cm. The
epidermis is green to dark blue grey, and become a clear powdery-grey in
the older part of the stem (like some Copiapoa)
Ribs: About 9-15.
Areoles: At the apex of tubercles, at first are covered with
yellowish-brown felt. The flower part of the areola is elongated, while
the upper part curves around the sides of the rib, more or less in the
shape of a small shield. As the tubercles widen in the course of growth,
the areoles become elliptical and almost glabrous.
Spines: 5 to 10 radial spines and 1 to 4 central spines, they are
all more or less of the same length in a given plant (± 0,5 -3 cm.), but
this species appears to be very variable regarding the length colour and number of spines in different populations.
They are usually black or
light brown at first, becoming grey or whitish-yellow as they age.
Flowers: Bell-shaped, 5 cm. long or less on lateral areoles, and
the segments of the perianth are sulphur or lemon-yellow (but also
white, orange or red), They have very hairy buds, The floral tubes
have brown-white hairs /bristles and dark spine-tipped scales.
The epidermis is dark-green to blue grey, and become
powdery-grey in the older part of the stem
(like some Copiapoa)
Cultivation: It is a summer-growing species
that offers no cultivation difficulty. Water regularly in summer (but do
not over-water). It needs good drainage and very porous soil. Keep
rather dry in winter. Feed with a high potassium fertilizer in summer.
It is quite frost resistant if kept dry (hardy to -12° C). It needs a
very bright exposure. Full sun is indispensable to keep plant compact
with strong spines.
Propagation: Direct sow after last frost,
offsets (if available).
Acanthocalycium thionanthum (Spegazzini)
Origin: Argentina (Salta)
Habitat: Mountain slopes
Conservation status: Listed in
CITES appendix 2.
- Echinopsis thionantha (Speg.)
- Lobivia thionantha (Speg.)
Britton & Rose
- Echinocactus thionanthus,
- Acanthocalycium thionanthum v.
chionanthum (Speg.) Hoss.
- Acanthocalycium chionanthum
- Echinopsis chionantha
- Echinocactus chionanthus
- Acanthocalycium catamarcense [F.
- Acanthocalycium brevispinum
- Echinopsis brevispina
- Acanthocalycium minutum
- Acanthocalycium thionanthum vminutum
- Acanthocalycium griseum
Note: This sp. is in the genus Echinopsis
now, and its accepted name is Echinopsis thionantha.
A full sun exposure
is indispensable to keep plant compact with strong and colourful spines.
Without sun the stems elongate, remain green and don't form the
Photo of conspecific taxa, varieties,
forms and cultivars of
plants belonging to the Acanthocalycium
Taxon has lots of synonyms (like
many other cacti), with
several controversial varieties and subspecies,
and comprises a multitude of different forms, but where each form is
linked to others by populations of plants with intermediate