Synonyms:

Opuntia geometricus
Tephrocactus alexanderi v. geometricus

Habitat:

Native to desert area from Argentina and south Bolivia, it grow in extreme heat and arid conditions.
In nature it forms low clumps composed of brown purple red ball-shape articles due to the strong sun exposure.

Description:

Tephrocactus geometricus is a small cactus with globular segmented of diameter about 4 -5 cm (2 inches) that can branch forming amazing clusters and it can grow up to 15 cm (6 inches) tall.
The ball-shape segments are usually without spines but if they are present you can see the black spines in the upper areoles.
The smooth blu-green skin of this cactus when exposed in full sun became purple-violet.
Flowers are very showy: white or light pink with yellow stamens, appears in summer time and last only one day.

Cultivation:

Cultivation is quite easy but T. geometricus does not tolerate water stagnation and for this reason it needs very draining soil, we suggest you to use inert materials like pumice or lapillus to mix with soil for cactus . We advise you to use a conical and quite deep pots that will help to accommodate the large root , it’s important that pots have holes at the bottom for sufficient areation and water will be able to easily dissipate after each watering.
In summer, durying the growing season you can water generously your T. geometricus but let it dry between one watering and the next it will prevent the roots. In winter months put it in a cool breezy area and stop to watering, it can tolerate light frost with temperatures going as -5 °C (23 ° F) if the soil is completely dry.
Tepherocactus geometricus need lots of sun and light but it is better to protect it during the hottest summer hours to avoid burns.

Propagation:

The more common way is the method of cutting , you can just cut the segments from the mature part of the plant and placed it in new soil.

Curiosity:

T. geometricus receives its name from the Greek word γεωμετρία (geometria).