palynological survey of the genus hypericum (hypericaceae) in iran and its taxonomic importance

In this research, pollen grains of ten species and two subspecies of the genus hypericum in iran belonging to four sections were studied using light and scanning electron microscopy. the pollen grains are monad, isopolar to subisopolar and heteropolar, prolate, subprolate, spheroidal and prolate spheroidal in shape, small to medium in size. the outline of pollen grains varies from round to triangular, quadrangular and ovate from polar view and elliptical, tetrahedral, quadrangular, round and ovate from equatorial view; 3 and 4 syncolporate to 3, 4 and 6 zonocolporate. based on exine sculpturing, pore shape, size and muri thickness, the examined species are divided in two main types including scrobiculate and micro reticulate and 2 subtypes including small pore / thick muri and large pore / thin muri. the pores are arranged from irregular to regularirregular with regular intervals. the current result revealed taxonomically important palynological data of the genus hypericum. these traits can be used for infrageneric classification, especially at sectional and species levels.