The wall vegetation of 15 villages at the northern foreland of the Harz mountains (Germany, Sachsen-Anhalt) have been investigated. In a whole 173 vascular plants have been recorded whereas the micro habitats wall joints and wall tops are reported seperately. 173 vascular plants have been found in/on walls, 153 of them in wall joints, 106 on wall tops. The most frequent species are common ruderal plants and weeds whereas the amount of pteridophyta is low. 37% of the whole species pool are aliens. There exists a positive correlation between the whole number of species and the number of the neophytes for the wall joints as well as for the wall tops. Our results show obviously no negative effect of the neophytes on the diversity of the wall flora
