New data on the morphology of pollen of Pulsatilla Mill. (Ranunculaceae)

The genus Pulsatilla Mill. represents a taxonomically complex group, with its systematic classification having undergone numerous revisions. Pollen grain morphology plays a crucial role in the intrageneric taxonomy of Pulsatilla; however, it remains unexamined for several species within the genus. This study presents the results of a comprehensive palynological analysis of 18 Pulsatilla species, including nine species investigated for the first time. The majority of species exhibited a 3-colpate aperture, including P. astragalifolia, P. bungeana, P. ajanensis, P. cernua, P. ambigua, P. taurica, P. kryloviana, P. herba-somnii, P. turczaninovii, P. multifida, and P. archarensis. A pantocolpate aperture was characteristic of P. herbertii and P. neobungeana, while P. campanella, P. andina, and P. neobungeana displayed a pantoporate aperture. The exine sculpture of all examined pasqueflowers was consistently microspinate, with predominantly smooth surfaces, except for occasional tuberculate textures. Pollen grain shapes varied from elongated ellipsoidal to spheroidal forms.