Definition of wall rue in English:

wall rue

noun

  • A small delicate spleenwort (fern) which resembles rue, growing on walls and rocks in both Europe and North America and sensitive to atmospheric pollution.

    • ‘The rusty back fern depends upon them for survival and walls host the polypody, spleenwort, wall rue and many others.’
    • ‘In the Black Country, wall rue is still found as an element of the "wall flora", thriving on lime-rich mortar in quite exposed conditions.’
    • ‘Look on the left for two kinds of ferns growing on the stone wall, these are the tiny wall rue and slightly larger maiden hair spleenwort.’
    • ‘Buildings, old walls and bridges can all support bats, bees and beetles, as well as lichens and mortar-loving plants such as wall rue.’
    • ‘The tiny A. ruta-muraria or wall rue is another lovely species in this genera.’
    • ‘In the British Isles, wall rue was considered a specific remedy for scrofula many years ago.’