Setiechinopsis mirabilis cactus plant

Setiechinopsis mirabilis Description: Setiechinopsis mirabilis  is a very small cactus (usually)solitary. The plants are easily grown from seed and providing good cultural conditions they may begin to flower in their second year.
Stem: Dark brown, cylindrical which seldom grows taller than 15 cm, 2.5 cm in diameter.
The plants seem to die long before this, and are best replaced with fresh seed-raised ones.
Flowers:  Last for only one night, but a number are produced in succession.
Blooming season: Summer, the blooms open at sun set and last only a few hours.
The spicy exotic perfume and long, narrow flower tube suggest that the natural pollinator must be a long-tongued moth.
Fruit: Drying at matutrity an opening laterally by a longitudinal fissures, with numerous seed.

Cultivation: This cactus is cultivated for its flowers and  is among the easiest species to grow, flower and propagate. Indicated for full sun or half shade exposure, water regularly from march to October, rot prone in winter, needs good drainage, It needs to be kept in a cool place during winter rest(can briefly tolerate temp. as low as -4°C) Stems may possibly become purple and limp in winter but revitalize in early spring. Occasionally theplants reach some 15cm tall, but this seems rare. The plants seem to die long before this, and are best replaced with fresh seed-raised ones.

Setiechinopsis mirabilis Fertilization: Feed with a high potassium fertilizer in summer.
Repotting: Repot in the spring, when their roots become cramped. Generally, they should be repotted every other year in order to provide fresh soil. After repotting, do not water for a week or more. Needs a large pot to accommodate a large root system.
Water: In summer, during the vegetative period, it must be regularly watered, but allowing the substratum to completely dry up before irrigating again (but do not overwater); in winter, it’s to be kept dry. Preferable not to water on overcast days, humid days or cold winter days.
Exposure: It needs bright sun, but, as a former mountain dweller, does not care for extremely high temperatures in summer.