Cleistocactus semaipatanus (Cárdenas) D.R. Hunt


Stems eventually to just over 1 m tall and 4 cm wide and with 14-16 ribs. Areoles close-set with 13-22 spines to 3 cm long. Flowers red, s-shaped, stamens and style projecting.



C. icosagonus (Kunth) Rol.-Gos. from S Ecuador and N Peru, which also has flowers widening towards the tip, has much longer flowers (7-8 cm) with a more or less straight tube.

Source: Thompson, A, ; Forbes, S.; Spencer, R. (1997). Cactaceae. In: Spencer, R.. Horticultural Flora of South-eastern Australia. Volume 2. Flowering plants. Dicotyledons. Part 1. The identification of garden and cultivated plants. University of New South Wales Press.

kingdom Plantae
phylum   Tracheophyta
class    Magnoliopsida
superorder     Caryophyllanae
order      Caryophyllales
family       Cactaceae
genus        Cleistocactus Lem.