Mimulopsis Schweinf. in Verh. K. K. Zool.-Bot. Ges. Wien 18: 677. 1868

– Type: Mimulopsis solmsii Schweinf.

= Ionacanthus Benoist in Notul. Syst. (Paris) 9: 65. 1940, syn. nov. – Type: Ionacanthus calcaratus Benoist.

The Malagasy monospecific genus Ionacanthus was synonymized with Mellera by Tripp & al. (2013a) on the basis of phylogenetic data derived from Sanger sequencing but was later included within a RADseq dataset (Tripp & Darbyshire, 2020) where it was resolved within Mimulopsis (including Epiclastopelma). This latter result better aligns with morphological features, as Ionacanthus shares with Mimulopsis the unique arrangement of the anthers in which the outermost theca of each of the longer pair of stamens has a conspicuous curved appendage, while the other thecae have much shorter appendages or lack appendages. Ionacanthus is therefore here transferred to Mimulopsis .