Palynomorphological study of Dianthus petraeus waldst. et kit. (Caryophyllaceae)

Abstract

The pollen morphology of Dianthus petraeus (Caryophyllaceae), which is endemic to the Balkans, has been examined by both light and scanning electron microscopy in order to provide taxonomically valuable characters that might be used in the classification of the Caryophyllaceae, as well as to contribute to the pollen atlas of Serbian apiflora. The pollen grains of D. petraeus are radially symmetrical, apolar, spheroidal and medium-sized. The mean of the pollen diameter is 45.5 +/- 1.4 mu m. The sculpturing pattern of exine is microechinate-microperforate, and the tectum is covered with minute echini averaging 0.8 +/- 0.1 mu m in length, more or less evenly distributed between the perforations. The microechini average number per sample area of 5 mu m x 5 mu m is 3.2 +/- 0.6. In view of the number, position and type of the apertures, the grains are polypantoporate, with about 13 operculate pores, averaging 6.4 +/- 0.7 mu m in diameter. Each operculum is covered with 4-6 conical spinules, which are longer than those on the exine surface. The obtained palynological results provide information that contribute towards a better understanding of the taxonomic status of D. petraeus.