EN
In this paper, mathematical values of habitats’ properties (waters and bottoms) of Juncus bulbosus communities (and others) are compared. Statistical analyses gave new information about an amplitude of some factors (19 properties for waters and 15 for bottoms). The study has confirmed that bulbous rush may also grow in eutrophic waters (it usually exists in oligotrophic, lobelian lakes or mesotrophic waters). An interesting fact was to find this species within habitats with a large content of calcium ions (systematic and floristic monographs state that this species avoids calcium ions). The rest of tested factors were also analysed. The results have shown that Juncus bulbosus phytocoenoses from Wrocław and its environs are very specific – they refer rather to communities of Potametea than to Littorelletea uniflorae class.