Parmelia sulcata forme saxicole.
This morph differs from the more common Parmelia sulcata corticolous form by its substratum: siliceous rocks, wall stones, or on the ground between rocks. Often colourless and dry, sterile. Rare in our prospection area. N.B. Not to be confused with Parmelia saxatilis saxicolous form which is very similar but with isidia and not soralia, and much more common.*