<italic>Neowestiellopsis</italic> gen. nov, a new genus of true branched cyanobacteria with the description of <italic>Neowestiellopsis persica</italic> sp. nov. and <italic>Neowestiellopsis bilateralis</italic> sp. nov., isolated from Iran.

Two strains of true branched heterocytous cyanobacteria, SA33 and SA16, isolated from dried paddy fields of Mazandaran, Iran, were studied using morphological, ecological, and molecular tools. Morphological characterization of the strains indicated them to be commonly showing profuse T-type branching, large irregularly shaped cells of main filament and tapering branches. Strain SA33 showed development of interesting biseriate filaments with unilateral branching, while strain SA16 showed uniseriate filaments with bilateral branching. Ecological examination of the localities consisted of the assessment of the habitat and correlations with the overall environment of the habitats. 16S rRNA gene-based molecular and phylogenetic assessment gave unique positioning to both the strains separated with good bootstrap support from rest of the members of the true branched clade. Full length sequencing of the 16S-23S ITS region and folding of the secondary structures gave interesting secondary structures and comparison with the closely related sequences clearly indicated the secondary structures of both the strains to be unique. All the results indicated the strains to be members of a morphologically cryptic but phylogenetically distinct unknown genus of cyanobacteria. Comprehensive evaluation of all the findings and comparative assessment of previous studies indicate that SA33 and SA16 are indeed two new species of a new genus of true branched cyanobacteria. In accordance with the International Code of Nomenclature for algae, fungi and plants, we propose the name of the new genus as <italic>Neowestiellopsis</italic> with the names of the species being <italic>Neowestiellopsis persica</italic> and <italic>Neowestiellopsis bilateralis</italic>. [ABSTRACT FROM AUTHOR]