Growing on siliceous rock. This is the location where I found almost all the specimens of Lasallia that I observed so far. In the case of fertile specimens those observed fit better in the species Lasallia hipanica than in Lasallia pustulata (the only two species in the genus existing here), due to the lack of isidia. Lasallia pustulata is by far the common species here, however I never saw it fertile before. This specimen called my attention in the field by its isidia very well developed occupying most of the thallus, contrary to the usual where it is restricted to the marginal zone. Not even then I noticed that it was fertile, only when I looked to the photograph. But, there is no doubt that this is a fertile Lasallia pustulata.