Flowers of Cleistocactus winteri, a member of the Cactaceae (cactus family) endemic to Bolivia. The picture shows groups of cylindrical flowers with red petals, with at their centre clusters of many anthers ( purple ) borne on white stamens. The green structures amongst the anthers (three visible) are the female receptive surface, the stigma. C. winteri is an easily grown and floriferous cactus producing long cylindrical stems, covered with golden spines (below and to left); giving rise to its common name of golden rat's tail cactus.In its native Bolivia, it is classified as an endangered plant by the IUCN. This is because it has a very restricted distribution, and is subject to collection from the wild. The plant is widely grown and easily propagated both by seed and by the rooting of detached branches