After collect a piece of the specimen in observation MO66901, but in a different place, I found this specimen, which I recognized to be very similar to the other. I collected a piece of it as well and made the microscopic analysis of both specimens together. The results obtained clearly show that, in fact, they belong to one and the same species. The microscopic analysis revelled - see the attached photos - a photobiont constituted by a green alga, with some big cells (up to 15 µm in diameter), spores mostly transversally 3-septate (average measures for the specimen in this observation: 17.5 x 4.4 µm (N=25)), and straight paraphyses ended with a globose cell. Searching for information about lichens with these characteristics I came to the genus Toninia. According to the first reference given bellow, in this genus there are two species common in Ireland (which my have some habitats very similar to the one of my observation in Portugal): T. aromatica and T. sedifolia, the former with 3-septate spores (with dimensions of 12-23 x 3-6 µm) and the latter with 1-septate spores. A full description of the species T. aromatica can be found in the 2nd reference, and pictures of specimens similar to mine can be found in the 3rd an 4th references. It should be also mentioned that, according to the 2nd reference, there are others Toninia spp. with 3-septate spores, including T. cinereovirens, T. hosseusiana and T. lutosa, but none of them seems to be as similar to my specimen as T. aromatica, which I believe to be the species that I looked for, taking into account that this species exists in Portugal (see the 4th reference).