Stems to 2 m or more long having 12-16 ribs. Areoles close-set with 15-20 spines to 4 cm long. Flowers curved upwards, orange or red.

Paraguay, Uruguay, NE Argentina

 

Other available species with mostly 7-14 spines include C. morawetzianus Backeb. from C Peru which has white flowers and C. smaragdiflorus (F.A.C. Weber) Britton & Rose from N Argentina which has characteristic green-tipped red flowers.

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.