This vegetation is dominated by the south-eastern European species Marrubium peregrinum, which is critically endangered in the Czech Republic. It occurs in dry ruderal habitats in villages, e.g. in lawns in which domestic fowl are kept, on village squares, on building rubble, at the bases of walls and along roads. It is an archaeophytic community that was more frequent in the past but which has declined in recent decades. Currently it occurs on a few sites in southern Moravia.