It will only be possible to give a few typical associations from the many that have been published. Crustaceous forms are the most abundant.

On granite and on quartzite not disintegrated Malinowski[1175] listed:

On granite and quartzite disintegrated:

On these disintegrated rocks there is a constant struggle for existence between the various species; the victorious association finally consists of Lecanora badia, L. cenisia and Lecidea confluens with occasional growths of the following species:

A number of rock associations have been tabulated by Wheldon and Wilson[1176] for Perthshire. Among others they give some of the most typical lichens on granitic and eruptive rocks:

On siliceous rocks in West Lancashire the same authors[1177] depict the lichen flora as follows: “There are many grey Parmeliae and Cladoniae with coral-like Sphaerophorei on the rocks, and on the walls smoky-looking patches of Parmelia fuliginosa and ragged fringes of Platysma glaucum and Evernia furfuracea. On the higher scars, flat topped tabular blocks exhibit black scaly Gyrophoreae, dingy green Lecidea (Rhizocarpon) viridiatra and mouse-coloured L. rivulosa. Suborbicular (whitish) patches of Pertusaria lactea and P. dealbata enliven the general sadness of tone, and everywhere loose rocks and stones are covered with the greyish-black spotted thallus of Lecidea contigua.”