A study of the trichomes types and distribution and pollen morphology was carried out in nine Micromeria taxa (M. cristata ssp. cristata, M. cristata ssp. kosaninii, M. croatica, M. graeca ssp. graeca, M. graeca ssp. fruticulosa, M. juliana, M. kerneri, M. longipedunculata and M. microphylla) and five closely related Clinopodium species (C. dalmaticum, C. frivaldszkyanum, C. pulegium, C. serpyllifolium and C. thymifolium) from the Lamiaceae family of the Balkan Peninsula. By scanning electron microscope, non-glandular trichomes, peltate and capitate trichomes were observed on the calyx, leaves and stem of the studied species. Two subtypes of capitate trichomes were observed in Micromeria species: subtype 1 (consisting of a basal epidermal cell and an elliptically shaped head cell) and subtype 2 (consisting of a basal epidermal cell, two to three stalk cells and a round head cell). In Clinopodium species, three types of capitate trichomes were observed: subtype 1, subtype 3 (consisting of a basal epidermal cell, a short peduncle cell, and a single round head cell), and subtype 4 (consisting of a basal epidermal cell, a stalk cell, and an elongated head cell). These results support the recent transfer of Micromeria species from the section Pseudomelissa to the genus Clinopodium.

Comparative palynological studies of Dipsacaceae s.str. show considerable diversity in the pollen grain morphology of its representatives. The aim of this research was to provide more detailed palynomorphological data on selected taxa whose pollen grains are characterised by tricolpate apertures (Pterocephalus plumosus, Succisa pratensis and Succisella inflexa). The pollen morphology of P. plumosus was studied using both light microscopy and scanning electron microscopy. The pollen grains are tricolpate, suboblate to prolate; large in size. Their outline in polar view (amb) is subcircular, rarely trilobate. The brevicolpi have a distinct margo and acute ends. The exine sculpture is echinate-microechinate-nanoechinate. The exine structure (columellae) of the pollen grains of P. plumosus, S. pratensis and S. inflexa was analysed for the first time in the current study. Pollen grains in P. plumosus are distinguished by long and dense columellae in the mesocolpia, and longer in the apocolpia. Our new ?alynomorphological data support a close relationship between S. pratensis and S. inflexa by the presence of shorter sparse columellae throughout the pollen exine. The UPGMA dendrogram shows the distinctive morphometric characters of P. plumosus pollen grains, which is thus included as a separate branch.

The research was carried out within the framework of project VI.52.1.2, "Analysis of the intraspecific structure of resource plants Version of Record 1127 TAXON 69 (5) • October 2020: 1126-1132 Marhold & Kuc ˇera (eds.) • IAPT chromosome data 32 in Asian Russia, selection and conservation of the gene pool" (No.