Ecologia Balkanica http://eb.bio.uni-plovdiv.bg University of Plovdiv “Paisii Hilendarski” Faculty of Biology ECOLOGIA BALKANICA 2023, Vol. 15, Issue 1 June 2023 pp. XX-XX Comparative data on the palynomorphological features of pollen grains of two Albania’s species of the Campanula pyramidalis complex (Campanulaceae) Blerina Pupuleku 1* , Donald Shuka 2 , Gëzim Kapidani 3 , Klea Trokoliçi 4 1 - University of Elbasan “A. Xhuvani”, Faculty of Natural Sciences, Department of Biology, pc 3001, Elbasan, ALBANIA 2 - University of Vlorë “Ismail Qemali”, Department of Biology, pc 9401, Vlorë, ALBANIA 3 - University of Tirana, Faculty of Natural Sciences, Department of Biology, pc 1001, Tirana, ALBANIA 4 - University of Elbasan “A. Xhuvani”, Faculty of Natural Sciences, Department of Biology, Student of Master of Science in Environment Protection, pc 3001, Elbasan, ALBANIA *Corresponding author: blerina.pupuleku@hotmail.com Abstract. Two Balkan species of the Campanula pyramidalis complex, respectively Campanula montenegrina and Campanula austroadriatica were analyzed based on comparative methodology for their palynomorphological features, and provided the evidence of similarities and differences of palynological features between them. Palynomorphological features of these species were described for the first time. Pollen grains of two species resulted to be triporate with circular pores, isopolar with radial symmetry, spheroidal shape in polar view and wide oval in equatorial one. The exine sculpture of pollen grains appeared echinate in all studied subpopulations, and it was accompanied by spinules in pollen grains of C. austroadriatica and pollen grains of C. montenegrina. The largest sizes of the pollen grains were identified at C. austroadriatica population collected near Perast, for the length of pores were identified at in pollen grains of Shirokë-Zogaj and Petrovac populations and for the width was identified in pollen grains of Shkalla e Tujanit and Kruja Castle populations. As for the exine, it was thicker at pollen grains of C. austroadriatica populations of Shirokë-Zogaj, Petrovac and near Perast localities. The smallest sizes for length of pollen grains and length of pores were found in C. austroadriatica collected at Shirokë-Zogaj, while for the width of pollen grains were found in pollen grains of C. austroadriatica collected in Montenegro populations and C. montenegrina of Albanian localities. The smallest width of pores was observed in pollen grains of C. austroadriatica collected in Petrovac. The exine was thinner in all populations of C. austroadriatica collected in Albanian localities. Key words: Pollen grains, palynological features, exine, C. austroadriatica, C. montenegrina. Introduction With more than 100 taxa, the bellflower genus is one of the largest in the western Balkan countries. Between them, Campanula pyramidalis complex is widely distributed and represented by five species, three of which Campanula austro- adriatica, C. montenegrina and C. versicolor occurs in Albania, Croatia and Montenegro (Janković et al., 2016; Janković et al., 2019; Lakušić et al., 2013; Shuka, 2018; Shuka et al., 2019). C. austroadriatica