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 characteristic powdery-grey coating.
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 characteristics):
Origin: Argentina (Salta)
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
Note: This sp. is in the genus Echinopsis
now and its accepted name is Echinopsis thionantha.
solitary or slowly branching through basal shoots.
Stem: Spherical in time 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 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 lower 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 about the length colour and
number of spines in different population. They usually are black or
light brown at first, becoming grey or whitish-yellow as they ages.
Flowers: Bell-shaped 5 cm. long or less on
lateral areoles and the segments of the perianth are sulfur- or
lemon-yellow (but also white, orange or red), They
have very hairy bud, The floral tubes have brown-white hairs /bristles
and dark spine-tipped scales,
Cultivation: It is a summer grower species
that offers no cultivation difficulties. Water regularly
in summer (but do not overwater ) needs good drainage and very porous,
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)
Need a very bright exposure, full sun
is indispensable to keep plant compact with strong spines.
Propagation: Direct sow after last frost, offsets