More than two thousand species of plants are known for the territory of the reserve. Of them: vascular - 822, bryophytes - 216, mushrooms - 464, algae - 317, lichens - 261.
Vascular plants. The Berezinsky Biosphere Reserve flora currently includes 806 vascular plant species belonging to 388 genera, 102 families, 55 orders, 7 classes and 5 divisions. The flora consists of 5 species of club mosses, 6 - horsetails, 16 - pteridophytes, 3 - gymnosperms and 759 - angiosperms. The latter consists of 203 species of monocotyledonous and 556 - bicotyledonous plants.
Ten families which total 55,0 % of the specific and 51,2 % of the generic flora composition are the most abundant in species. The rest 92 families are characterized in the following way: 2 are represented by 20-25 species, 53 - by less than 20 species in each and 37 - by only one species in each. Amongst genera Carex and Salix ones occupy the leading position.
Species, directly or indirectly related to human's activity (synantropic plants) constitute considerable part of the reserve flora (17,6 %). Weeds, accompanying plants grown in crop fields and kitchen-gardens, and ruderal plants growing at roadsides and dust-place also belong to this category.
Among field weeds Apera spica-venti, Cirsium arvense, Fallopia convolvulus, Raphanus raphanistrum etc. can often be found. Stachys annua and Agrostemma githago, which have not been recorded during the previous 20 years, appear to be rare species.
Capsella bursa-pastoris, Chenopodium album, Galeopsis ladanum, G. bifida, Fumaria officinalis, Stellaria media etc. dominate among segetal-ruderal plants. Atriplex patula, Neslia paniculata, Sinapis arvensis occur rarely.
Among ruderal plants Arctium lappa, A. minus, Artemisia absinthium, A. vulgaris, Berteroa incana, Polygonum aviculare, Potentilla anserina, Sonchus oleraceus, S. asper, Urtica urens etc. are the most widespread. Chenopodium hybridum, Nepeta cataria, Hyoscyamus niger sometimes occur.
Some species, i.e., Amaranthus retroflexus, Anchusa officinalis, Anthemis cotula, Bromus mollis, Cichorium inthybus, Mimulus guttatus etc. appear to be alien.