Acta Palaeobot. 42(1): 51–61, 2002 Pediastrum species (Chlorophyceae) in Quaternary sediments of “Z ˙ abie Oko” peat bog in the Tatra Mts. KONRAD WOLOWSKI 1 , ANDRZEJ OBIDOWICZ 2 and IWONA WAWRZYCKA 1 W. Szafer Institute of Botany Polish Academy of Sciences, Lubicz 46, 31-512 Kraków, Poland 1 Department of Phycology; e-mail: wolowski@ib-pan.krakow.pl; iwaw@ib-pan.krakow.pl 2 Department of Palaeobotany; e-mail: obidowicz@ib-pan.krakow.pl Received 18 December 2001; accepted for publication 11 March 2002 ABSTRACT. Six taxa: Pediastrum boryanum var. boryanum, var. longicorne, var. brevicorne, P. integrum, P. orientale, and P. duplex var. rugulosum were found in fossil Quaternary sediments (Late Glacial, Holocene) from the “Z ˙ abie Oko” bog in the Tatra Mts. All of them are described and original documentation is added. KEY WORDS: Pediastrum, Chlorophyceae, Interglacial, Late Glacial, Holocene, Tatra Mts., Poland INTRODUCTION The taxonomical research of the genus Pedi- astrum in fossil sediments, e.g., lake and peat bog deposits in Poland have not been carried out. Only general information about the occur- rence of genus Pediastrum was to be found in the papers concerning fossil flora (Krupin ´ ski 1988, 1992, 1993, 1996, 1997, Krupin ´ ski & Marks 1985, Bin ´ ka et al. 1991, Lindner et al. 1991, Latalowa 1992, Janczyk-Kopikowa 1991, Zachowicz et al. 1982). More detailed informa- tion about P. boryanum is given by Harmata (1995). Pidek (2000) gives information con- cerning several varieties of P. boryanum, P. du- plex, P. alternans, P. kawraiskyi, and P. sim- plex which have been found in profile Zdany and Brus (Lublin Upland, Poland). Many data on fossil Pediastrum come from southern Eu- rope, mainly from the Czech Republic: Jankov- ská and Komárek (1982, 1995), Pokorny and Jankovská (2000) and Russia: Jankovská and Komárek (2000), Komárek and Jankovská (2001). Very interesting data on environmental preference of fossil Pediastrum from south- western Denmark were given by Nielsen and Sorensen (1992). MATERIAL AND METODS The samples were taken from the core of the peat-bog “Z ˙ abie Oko” located in the Valley of Rybi Potok at the “Morskie Oko” lake in the Tatra Mts. (alt. 1390 m). The material, 1 cm 3 in volume was taken at intervals of 2–10 cm by Obidowicz (1996). The 1 cm 3 sediments samples were treated by Erdtman’s acetolysis. Sam- ples with mineral content were treated with HF prior to acetolysis, and glycerin slides were made. The taxo- nomical research was carried out using LM Carl Zeiss Jena. In each slide the number of coenobia and their fragments was counted in six horizontal and perpen- dicular fields (numbers of coenobia fragments were divided in two). For each species found microphoto- graphs and drawings were made. TAXONOMICAL DESCRIPTIONS The keys of Komárek and Fott (1983) and Jankovská and Komárek (1995) were used for determining of the taxa. Pediastrum boryanum var. boryanum (Turp.) Menegh. Pl. 1, figs 1–5 Coenobia usually circular, without holes be- tween cells, with 16(–32) cells. Marginal cells