This species is characterized by its small triangular stipules, medium-sized leathery leaves with the venation finely, densely reticulated and raised on the lower surface, terminal cymose inflorescences, short calyx lobes, and medium-sized purple to nearly black corollas. It is similar to Danais rubra and Danais terminalis. 

Puff & Buchner (1994) reported Danais nigra from northern and east-central Madagascar, and did not see the fruits. They provisionally included Danais perrieri as a synonym of Danais nigra. However, Danais nigra was circumscribed differently and more narrowly by Taylor et al. (2024), who included the plants from northern Madagscar in this species and separated both Danais perrieri and the east-central plants, and put the latter in Danais puffiana.