Habitat: Paraguay,
northeastern Argentina, Brazil, Peru. Description: a genus of clumping cacti whose slender stems are up to
2 metres (6.5 ft) long with more or less rounded ribs (up to nine) bearing
circular areoles with variable spination. The nocturnal, fragrant flowers
are borne on old branches during the summer or autumn. The monstrose form
may occur. The genus has been divided in two; some are now part of
Acanthocereus, the remaining of Cereus. Soil: mineral mix. Location: grow in filtered sunlight. Temperature: the minimum should stay around 8-10°C (46-50°F). Water: average. Cultivation tips: they grow rapidly and need to be tied to a support.
Propagate from cutting. They are prized for the showy flowers. Main species:
M. spegazzini;
M. campinensis; M. saxicola;
M. cavendishii; M. marmorata.