Apiognomonioides was introduced based on the sexual morph. Kaneko & Kobayashi (1984) showed Apiognomonia as having two celled ascospores in which the upper cell was larger than the basal cell, however, A. supraseptata is distinct in having a smaller upper cell. Subsequently, Harrington & McNew (2018) suggested that A. supraseptata represents the only clearly demonstrated sexual morph of Tubakia. Owing to its isolated position in the LSU tree in Tubakiaceae, but distant from all other genera in this family, Apiognomonia supraseptata shows its phylogenetic distince from all other genera in the LSU tree of family Tubakiaceae (Braun et al. 2018). Apiognomonioides supraseptata and the sexual morph of Tubakia suttoniana have similar morphology (rostrate perithecia, unitunicate 8-spored asci, colourless conidia), but A. supraseptata differs in forming uniseptate ascospores with a septum near the apex (Braun et al. 2018).