Psathura is similar to Psychotria, and most authors acknowledge that Psathura should be included within Psychotria but continue to recognize it. It is separated based on its 3-5-locular ovaries and fruits and 3-5 stigmas, vs. 2-locular with 2 stigmas in Psychotria. The genus Psathura has been recognized in recent years by Bremekamp (1963) and Verdcourt (1989) for eight species found in Madagascar, the Mascarenes (3 species), and the Seychelles (1 species). When the multilocular ovary is disregarded, Psathura as circumscribed by them appears to comprise at least two distinct groups of species, one in Madagascar and one in the Mascarenes, and the species from the Seychelles does not appear to be closely similar to either of these.
The species of Psathura in Madagascar are fairly similar and probably closely related to each other. They all share generally similar stipules, leaf general aspect, a lax, cymose, pedunculate, rather corymbiform inflorescence arrangement with the basalmost pair of secondary axes well developed and often as long at the primary axis, and fruit size. None of the Psathura species in Madagascar is well documented, with the flowers in particular pooly known probably because the flowering plants are not easy to separate from Psychotria due to the multilocular ovary not being very evident.
There has been some confusion about the name and distribution of one Psathura species in Madagascar: Bremekamp described it as a new species from Madagascar but mistakenly used for it the specific epithet "polyantha", which was previously published for a different species, Psathura polyantha Cordem., that is found only in Reunion. Verdcourt later published the replacement name Psathura batopedina for the species from Madagascar.