Body solitary or in groups. Areoles elliptic. Spines 30-40, all more or less similar, the central ones slightly larger, variously bristly, yellow or white. Flowers funnel-shaped, curving upwards bright orange to red. Fruit purple. [R. muscula Ritter & Thiele]

Bolivia, NW Argentina

 

R. spinosissima Backeb. from N Argentina differs in having bristle-like white spines with the central one brown-tipped.

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.