New records of heterocystous Cyanophyta from paddy fields of Iran

Four paddy fields in Guilan province in the north of Iran seasonally were sampled from April 2008 to January 2009. Twenty-two morphospecies belonging to three families of the heterocystous blue-green algae were identified. Fourteen species and one variety of these taxa are new record for Iran. Among the families Nostocaceae with six genera and 16 species showed the highest species richness