Karyotypic study of 13 populations belonging to 7 Iranian Lotus species was performed for the first time. The study showed x = 6 and 7 are available in Iranian Lotus species; all taxa studied, except for, L. corniculatus (4x) were diploid. The studied species varied in their karyotypic formulae and symmetry. They also differed significantly in their total chromatin length as well as size of long arms and short arms of chromosomes, indicating the occurrence of both structural and quantitative changes in their karyotypes during the species diversification. Clustering of the Lotus species based on karyotypic features partly supports their taxonomic treatment.
Keywords: karyotype formulae, Lotus, symmetry, populations, Iran.