The plant communities dominated by Rumex obtusifolius in Slovakia are
described. These include: the Arctio tomentosi-Rumicetum obtusifolii P
ASSARGE 1959, the Rumicetum sylvestris KULCZYNSKI 1928 (incl. 2 new su
bassociations, such as the plantaginetosum majoris and the ligusticeto
sum mutellinae). The descriptions are based on 65 releves. Some syntax
onomical problems on monodominant plant communities were briefly discu
ssed.