A small adder averaging around 30 cm with a maximum length of 42 cm. The Red Adder is endemic to the Western Cape and adjacent Northern Cape as well as the extreme western Eastern Cape where it inhabits rocky mountain slopes in succulent Karoo and Fynbos. Individuals are often found sheltering under rock slabs.

Like many other small adders it is largely active in the early mornings and late afternoons and is fond of hiding under shrubs or rocks. The horns, if present, are highly reduced. Females produce 3 – 11 young in late summer. It feeds on lizards, mainly geckos, skinks, agamas and lacertids but also takes small rodents.

The venom of this snake is thought to be similar to that of other small adders, causing pain and swelling.