The holotype of Oxygyne frankei, collected in 1928 by a pastor named Charles Tisserand (Tisserand 2623) 40 km north of Bambari/Central Arfican Republic, has long been stored in the private collection of Georges le Testu, misidentified as a parasitic flowering plant, namely Hydnora sp. (Hydnoraceae). After his death, le Testus collection went to the Herbarium of the British Museum of Natural History/London. In 1983, Luis Diego Gomez Pignataro, an ecologist from Costa Rica, made the annotation "Thismia intermedia sp. nov. Holotypus" to the sheet. The next annotations are from Thassilo Franke, formerly based in the University of Munic and author of descriptions of several mycoheterotrophic plants (Triuridopsis intermedia, Afrothismia foertheriana, A. saingei, A. hydra, A. korupensis). In 2002 he wrote "Oxygyne sp." and added "Oxygyne sp. nov" in 2008 (Cheek et al. 2018), therefore being the first to recognize this specimen as a new Oxygyne.
The formal description was undertaken in Cheek et al. (2018), stating the closest affinities to Oxygyne triandra due to the shape of perianth lobes, the relatively short annulus around the perianth opening, and stigma morphology, but differing in the shape of the annulus lamellae, and color and length of perianth lobes.
A second descripton exists based on Tisserand 2623 in 'The global Flora' edited by Christenhusz, Fay & Byng (2018), naming the specimen Oxygyne confusa Bidault, Merckx & Byng. This publication is prior to Cheek et al. (2018), however, according to Cheek et al. (2018) the work is currently listed as 'Opera Utique Oppressa' by the International Association of Plant Taxonomy, and, hence, the including species descriptions are not yet validly published according to Article 34 of the ICN.