A geobotanical survey of rich fens on the left-bank terraces of the Em-Egan River, the right tributary of the Malaya Sosva River in the southern part of the nature reserve “Malaya Sosva” (61.79° - 62.05° N, 64.06° - 64.55° E). 179 species have been identified, including 84 species of higher vascular plants, 69 species of mosses and 26 types of liverworts. Of these, 11 species are included in the Red Data Book of the Khanty-Mansi Autonomous District, including 9 species of higher vascular plants and 2 species of mosses: Baeothryon alpinum, Cardamine nymanii, Dactylorhiza traunsteineri, D. incarnata, Hammarbya paludosa, Huperzia selago, Saxifraga hirculus, Thelypteris palustris, Triglochin palustre, Meesia triquetra, Paludella squarrosa. Three more species – Corallorrhiza trifida, Calliergon richardsonii, Meesia uliginosa are included in the list of species whose condition in the natural environment requires special attention. In addition, such rare species as Eriophorum brachyantherum, Stellaria crassifolia, Bistorta major, rare species of mosses such as Bryum bimum, Calliergonella cuspidata, Campylium pretense, Hamatocaulis vernicosus, Scorpidium cossonii, Tomentypnum nitens are listed in the mire plant communities.

On the basis of the ecological-floral approach of the J. Brown-Blanke school, 8 associations, 6 subassociations and 3 communities from 5 unions, 3 orders and 3 classes of vegetation were allocated in the vegetation cover of rich fens. The belonging of one more vegetation community type of the Bistorta major–Sphagnum fuscum dwarf birch community with the sparse fir (Picea obovata) to the class and the order is not established. The highest phytocenotic diversity and the highest concentration of rare and protected species are found in communities of the order Sphagno warnstorfii-Tomentypneetalia. Phytocenotic association and frequency of occurrence of rare species in different types of plant communities are established.