The morphology, anatomy, chemistry and ecology of some corticolous and lignicolous species of Buellia from the Iberian Peninsula that contain secondary lichen compounds are discussed, including B. chloroleuca, B. disciformis, B. erubescens, B. hyperbolica and B. leptoclinoides. These species are compared with other corticolous Buellia species that occur outside the study area, including B. arnoldii, B. insignis, B. regularis and B. sanguinolenta. The misunderstood B. zahlbruckneri J. Steiner and B. jorgei, are synonyms of B. erubescens, and the invalid taxon B. zahlbruckneri sensu Schauer non Steiner and B. poeltii, are synonyms of B. chloroleuca. New chemical data on several taxa are reported. A key to the pecies and illustrations of their ascospores are provided.