One of the earliest described species of the cyanobacterial genus Leptolyngbya, L. foveolarum, lacks type material, known autapomorphy, and an unambiguous position in 16S rDNA phylogenies. Missing diagnostic features hinder the reliable identification of this species. In this study, we compared strains of putative L. foveolarum with the type species of the genus, L. boryana, and Nodosilinea spp. which share overlapping morphological features and ecology with L. foveolarum. Our results show that both L. boryana and the genus Nodosilinea form distinct clades, whereas strains identified as L. foveolarum are scattered at various positions in the 16S rRNA gene tree. After considering the morphological, ecological, and molecular data, and MALDI-TOF MS spectra, we propose combining L. foveolarum with Nodosilinea as Nodosilinea foveolarum comb. nov. Moreover, our observations enable easier identification of representatives of both genera Leptolyngbya and Nodosilinea, which are among the most common filamentous cyanobacteria in soil and freshwater environments. Based on the results of our analyses, we also propose to transfer Monilinema alkalinum to Leptolyngbya alkalina comb. nov.
Dřímalová et al. (Fri,) studied this question.