floristic study on the algae of siahdarvishan river in guilan province, north iran

in the present study the freshwater algae of siahdarvishan river were sampled on a montly basis from december 2007 through november 2008. three sampling stations (gaght roudkhan , shahkezr dame and talab laleh ) were chosen in the river. some physical and chemical parameters (water temperature , total hardness , nitrate , nitrite, phosphate and ph) of water samples were measured. a total of 84 species were identified including: chlorophyta, 36 species; cyanophyta, 24 species; bacillariophyta, 20 species; rhodophyta, 2 species; euglenophyta and xanthophyta each with 1 species. among the families, oscillatoriaceae with 14 species showed the highest species richness. taxonomic keys to genera and species are presented to facilitate the identification of algal flora of the region.