The thallus of this specimen clearly points to a Cladonia species. Hovewer, no apothecia is present. Looking in the net for information about sterile species of cladonia I found references to three species: C. apodocarpa, C. caespiticia and C. petrophila_. For the later I was not able to find any image. For the other species I found images in Sharnoff Photosindex.html and observations in the MO database, MO45175 for C. apodocarpa and MO21295 for C. caespiticia. The squamules of C. apodocarpa are of a different form than those of my specimen, but the squamules of C. caespiticia from the above cited observation are very much like those of my specimen. In Sharnoff Photos a photo of a specimen with podetia can be seen. Thus I think that C. caespiticia is a possiblity for the classification of this one.