Ocellomma picconianum

Crustose, thallus white ecorticate. Apothecia 0,2-0,5mm across, black disc often white pruinose; white thalline margin with large crystals of calcium oxalate. Epithecium brown, hymenium colourless. Hypothecium colourless to pale brown, I+ blue, K/I+ violet. Asci 8-spored, with I+blue ring in tholus. Ascospores 3-setptate, hyaline, 24-28 x 4-5 μm.

Reproduction: mainly sexual.

Photobiont: Trentepohlia

Spot test: thallus K-, C-, KC-. P-, UV-

Chemistry: thallus with Roccellic acid.

Habitat: On bark in humid woodlands.

Distribution: Mediterranean-Atlantic. 

 Hypothecium colourless to pale brown, I+ blue, K/I+ violet

Photobiont: Trentepohlia

Position in classification: Roccellaceae, Arthoniales, Arthoniomycetidae, Arthoniomycetes, Pezizomycotina, Ascomycota, Fungi
Locality data:
Location: Monestir de Sant Benet, Sant Fruitós del Bages (Bages)
Ecology: On Robinia pseudoacacia.
Altitude: 234 m
Climate: Subhumid Continental Mediterranean (Tmm=13-14,0ºC, 550-600 mm)
 
Etimology: The name Ocellomma refers to the small ascomata with often whitish margins contrasting against the disc and which makes them look like small eyes. (Ertz, D., Tehler, A., Irestedt, M., Frisch, A., Thor, G. & van den Boom, P. (2015) A large-scale phylogenetic revision of Roccellaceae (Arthoniales) reveals eight new genera. Fungal Diversity 70: 31–53. https://doi.org/10.1007/s13225-014-0286-5 )