Floristic diversity of the Lower Ob river floodplain in the Yamalo-Nenets autonomous okrug

Information on the flora of the Lower Ob River floodplain being about 500 km long within the Yamalo-Nenets Autonomous Okrug (YNAO) has been summarized for the first time. The taxonomic diversity of the floodplain flora is considered in the latitudinal aspect. The total number of taxa is 322 including 301 species, 18 subspecies and three species variations. The taxa belong to 155 genera and 56 families. They are given in the alphabetical order. The floristic richness of floodplain vegetation changes and the Sørensen coefficient between floras of the study areas decreases from south to north are shown. 21 % of taxa are found throughout the whole floodplain territory. The proportions of the identified flora are considered in comparison with the floodplain flora of the Middle and Upper Ob. The authors have found new habitats of four taxa listed in the Red Data Book of the YNAO (2010), four from Appendix 1 of the Red Data Book and 29 taxa being rare for the territory of the Okrug, including two listed for the Okrug for the first time.