Maihueniopsis glomerata subsp. hypogaea ( Maihueniopsis molfinoi, Opuntia molfinoi, Maihueniopsis hypogaeus, Opuntia hypogaea)

Small clumping cactus. Cactus with sub-cylindrical articles, with a narrower tip, slightly tuberculated, green, 2-4 cm long. Central spines flattened and pointed (pricking), sparse, white, up to 10 cm long; secondary spines bristly. Yellow flowers up to 5 cm long. Native species of north-western Argentina, southern Bolivia and north-eastern Chile. The species grows in the puna habitat between 500 and 4,000 meters, in flat sandy or clayey areas and on stony hills. The plant has a taproot as large as a carrot and grows best in long pots with well-drained and sandy soil with a little pumice. Exposure to full sun. Water every 10-20 days between March and October, never in winter. If kept very dry in winter it can withstand temperatures down to -10 ° C but does not tolerate the scorching heat of summer. In nature it remains buried under snow for long periods, so if the cold is very intense, it would be better to cover the plant with a layer of mulch.