EN
Low percentage of Lolium perenne on phytosociological releves of plant communities of Molinio-Arrhenatheretea, orders Molinietalia (1.0%) and Arrhenatheretalia (12.4%) and high in Plantaginetalia maioris (75.0%) was found due to studies performed. The highest percentage of Lolium perenne was observed on phytosociological releves of Lolio-Cynosuretum pasture community (78.3%) and treaded Lolio-Plantaginetum (75.0% ), but only 10.1 % in cut-pasture community of Poa pratensis + Festuca rubra in Wieprz river basin. Set of tall grasses Arrhenatheretum medioeuropeum was characterized with significant percentage of Lolium perenne (27 .5%). In total, only 9.2% of Lolium perenne, 62.3% of Festuca rubra and 78.7% of Poa pratensis percentage was found on phytosociological releves of plant communities from three discussed orders of Molinio-Arrhenatheretea class.