According to worldofsucculents.com, this cactus is a genus of columnar cacti native to mountainous areas of Peru, Uruguay, Bolivia and Argentina. These cacti grow in large shrubby clumps mixed with other vegetation or clamoring over boulders. The genus name comes from the Greek "kleistos," meaning "closed," and refers to the flowers that hardly open.
Many of the features of this genus are small but profuse. The stems are typically only 2.5 cm in diameter. However, they branch readily at the base to form noticeable clumps. The spines, in general, are likewise small and flexible but, in most cases, are very numerous, even to the point of obscuring the stems.
This trait is continued with the flowers. Many species have flowers that resemble little tubes of lipstick or firecrackers. Yet, the stems may be full of these flowers with many buds in the making.
They prefer well-drained soil and full sun, and minimal water during winter.