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.