taxonomic study on cyanobacteria species in natural habitats of tanacetum parthenium emphasising on wollea and cylindrospermum morphological characters

Floristic study of cyanobacteria in the terrestrial habitats of iran, revealed several taxa belonging to seven genera. soil samples were collected from natural habitats of medicinal plant, tanacetum parthenium, located in four provinces of iran (qom, isfahan, lorestan, razavi khorasan provinces). all provinces studied are located in semiarid regions of the country. the results of this study indicated the presence of 13 species belong to three families of cyanobacteria. among these families, nostocaceae with four genera and eight species showed the highest diversity, whereas rivulariaceae with one genera and one species exhibited the lowest diversity. among several heterocystous and non heterocystous taxa, nostoc and oscillatoria were found to be the most dominant genera in almost all the studied sites. two reported species of genera wollea and cylindrospermum in present study, also have limited distribution in terrestrial habitats of iran. therefore, part of the current systematic study has been done with emphasis on these two specific taxa. a distribution of local area and camera lucida pictures of identified taxa is subjected in this study.