Examination of type material for Ulnaria splendens, Ulnaria aequalis and Ulnaria obtusa provides evidence to support each as a distinct and definable taxon. None can be considered more closely related to any other species in the genus Ulnaria and are therefore all recognised at the same rank, that of species. We briefly
discuss five further taxa that involve the name Synedra splendens: Synedra splendens var. marina, Synedra splendens var. salina, Synedra splendens var. brevis, Synedra splendens var. subspathulata and Synedra (ulna var.) spathulifera.