Melanelixia glabratula forme saxicole
This taxon is an intermediate between Melanelixia glabratula and Melanelixia fuliginosa, and differs from Melanelixia glabratula that grows on smooth bark trees by its habitat: rocks, most frequent colours dark greenish, margins paler and darker towards the center. Usually isidia are less numerous. Ovoid spores 10-13 (15) x (4) 5-8 (10) µm according to our measurements.
N.B. It seems that the interpretation of this taxon was either Melanelixia glabratula darker than the bark form or a paler form on rocks of Melanelixia fuliginosa with green colors. It would deserve additional investigations to conclude on the appropriate taxonomic ranking.