[3] This plant has simple, undivided leaves, typical of the family.

[citation needed] Pentanisia angustifolia is found in eastern South Africa, Lesotho, eSwatini,[1] and Mozambique.

The specific epithet is derived from Latin, "angusti-" coming from "angustus," meaning "narrow" or "tight" and "-folia" coming from "folium," which means "leaf," hence the "narrow-leaved" reference in this flower's common name.

[citation needed] Synonyms include Diotocarpus angustifolius Hochst.

[2] The genus Diotocarpus was revised alongside other herbaceous Rubiaceae in 1952, having been considered a taxonomic synonym of Pentanisia.