Setiechinopsis mirabilis (Echinopsis mirabilis)

Small cactus up to 15 cm tall. Cylindrical stems of grey-greenish colour, sometimes with purple shades, not clumping. Long and thin spines, grey-black in colour, very numerous. Apical flowers formed by a long tube that opens, at the apex, in a disk of thin and very numerous white tepals. Flowering occurs during the night. Native species of eastern Argentina where it grows on the edges of salinas and in mountain scrub, often under shrubs and in flat prairies up to the base of mountains from 0 to 1000m. It requires well-drained soil and a position in full sun or partial shade. Water every 10-20 days from March to October and keep completely dry the rest of the year. Hardy up to -4°C (for short periods).