Pollen of the Antarctic plants Colobanthus quitensis and Deschampsia antarctica and its representation in moss polsters

Formation, structure, and representation in moss polsters of pollen grains of Colobanthus quitensis (Kunth) Bartl. and Deschampsia antarctica Desv. (the only two native flowering plants growing in Antarctica) were investigated by means of light microscopy. Microsporogenesis and male gametogenesis of both investigated plant species proceded in the way typical of other angiosperms. C. quitensis forms spherical, two-nuclear pollen grains enveloped by the thick polyporate sporoderm. Pollen grains of D. antarctica are three-nuclear, and their sporoderm contains one aperture. Both investigated species form chasmogamic and cleistogamic flowers. In moss samples, collected according to Pollen Monitoring Programme method, the local element - Poaceae and Colobanthus prevailed. The Poaceae pollen type includes mostly Deschampsia, but other grains, such as Poa annua, which was reported to grow in the vicinity of H. Arctowski Station, cannot be excluded. Among long-distance elements, Nothofagus pollen prevailed. One to seven pollen grains of this tree were found in each sample, which had been transported by strong westerly winds from southern South America. All the examined spectra also contained numerous fungal spores and other unidentified (probably non-sporomorphous) elements.