The name honors a Danish botanist Nathaniel Wallich, who discovered this species. It is a medium-sized succulent shrub that grows up to 80 cm in height. It produces a branched stem, covered with a greyish-green bark; it is made up of numerous tubercles, from which cylindrical leaves grow, that are slightly flattened on the top, up to 12 cm long, of a light green color. In summer, its tubular greenish-yellow flowers bloom.