Cleistocactus samaipatanus

Native to Bolivia and Mato Grosso, Brazil, it is a cactus with slender, ribbed stems that branch from the base. The stems may grow upright, lean or sprawl. Closely spaced clusters of yellow or brown spines become gray with age. Bright red flowers develop along the stems, with a curved tube and spreading flower segments surrounding projecting purple stamens. The small, rounded fruits become reddish brown and bear hairs. In Bolivia, the species grows on cliffs and steep slopes in seasonally dry valleys. Photographed in Peru.