Cactus e Dintorni

Habitat: Andean ranges of Bolivia, Argentina and a few other South American mountainous regions; they occur mostly at high elevations (up to 3000 m / 9800 ft) so they’re adapted to great diurnal temperature variations and high levels of solar radiation.
Description: these small, globular plants, often forming clumps, have tubercles arranged in a spiral and are rather short-lived. They can flower even when very young, typically from the spring through to summer. The flowers may be from red or orange to yellow and white. It was once within Echinocactus  and now contains Aylostera, Digitorebutia, Sulcorebutia, Weingarthia. Some scholars believe that Mediolobivia is also to be included.
Soil: fertile mix; half inert materials plus half organic matter.
Location: suitable for a south or south-east facing wall; they will do best if they receive the morning sun. Light should be dappled or filtered during the hot months. They enjoy fresh air and resent hot, damp conditions.
Temperature: the minimum should stay around 5°C (41°F).
Water: start watering in the spring when flower buds are being formed and increase the frequency in May and June. Some water spray mist is sufficient during July and August but it should be done quite often. Suspend watering when the flowering period has come to an end, except for some occasional spraying.
Cultivation tips: easy; repot once every two years in the spring. They are susceptible to summer heat and spider mite attack. Allow the plants to rest from mid-October to the end of March. They are readily propagated from seed or by rooting offsets. Fertilize regularly adding some microelements. Because of their taproot, they’re best grown in deep pots.
Main species of Rebutia: Rebutia marsoneri, is dwarf, globular with a depression at the growing tip with yellow flowers; needs full sun, plenty of water in the summer, humus-rich soil and a minimum around 4°C (39°F); Rebutia aureispina; Rebutia albopectinata; Rebutia buiningiana; Rebutia cajasensis; R. chrysacantha; Rebutia deminuta; Rebutia fulviseta; Rebutia grandiflora; Rebutia perplexa; Rebutia pygmaea, dwarf, clumping with beetroot-like root enjoys full sun; it comes in many different varieties; R. fiebrigii; Rebutia narvaecensis (Aylostera), a mountain cactus; grow in dappled shade, good ventilation and spray water frequently;
Rebutia steimannii, Rebutia raulii; R. fusca (Aylostera) they all resent excessively hot conditions and need plenty of air;
Rebutia krainziana; Rebutia heliosa, with a large beetroot-like root; quite troublesome; R. huasiensis; R. kieslingii; Rebutia mamillosa; Rebutia minuscola; Rebutia pseudodeminuta; Rebutia pulvinosa; Rebutia sanguinea; Rebutia senilis; Rebutia spinosissima; Rebutia vallegrandensis; Rebutia x