Stomatal cell length and ploidy level in four taxa belonging to the Phleumsect. Phleum

Stomatal cell length was examined in four closely related taxa of sect. Phl eum in the genus Phleum (P. nodosum, P. pratense and in two cytotypes of P. commutatum). It was found that the polyploid taxa (P. pratense, 2n = 6x = 42 and P. commutatum, 2n = 4x = 28) have longer stomatal cells than their d iploid relatives (P. nodosum, 2n = 2x = 14 and P. commutatum, 2n = 2x = 14) . In these two pairs of taxa, stomatal cell length can be a rapid and usefu l indirect ploidy level indicator and can assist in their identification. M aterial taken from live and dried specimens of a given taxon did not differ in stomatal cell length, meaning that different cytotypes can be identifie d from herbarium material as well.