porpidia crustulata?

growing on top of an exposed wall. has similarities to this lichen: http://www.projectnoah.org/spottings/12356619 judging by zachs spotting on mushroom observer, Caloplaca lactea should have a bright red reaction to 'K' which I think is short for KOH (potassium hydroxide): http://mushroomobserver.org/image/show_image/320728?obs=131433&q=1ApVP Porpidia superba? http://liquenfreak.blogspot.co.uk/2009/06/crustaceos-de-ancares.html Porpidia crustulata? http://lichenportal.org/portal/taxa/index.php?taxon=55333&taxauthid=1&c… Porpidia macrocarpa? http://lichenportal.org/portal/taxa/index.php?taxon=55340&taxauthid=1&c… Lecanora sp. http://mushroomobserver.org/131609?q=1BMru?