Diploschistes muscorum

Thallus crustose, white-grey, episubstratic, often starting the development on squamules of Cladonia.

Reproduction: Apothecia 1-2 mm; semi-immersed in the thallus; disc blackish pruinose with a raised thalline margin. Asci 4-spored. Spores muriform, brown, ellipsoid, 18-35 x 6-18 µm; transverse septa 4-6, longitudinal septa 1-2 per transverse segment.

Photobiont: Chlorococcoid.
Spot tests: K+ yellow to red, C+ red, KC-, P-, UV-.
Chemistry: Diploschistesic and lecanoric acids (both major).
Habitat: Terricolous, starting on Cladonia squamules, then in mosses and finally on carbonate soils. Photophile.
Distribution: Cosmopolitan, Mediterranean in open habitats, temperate and polar regions and extending to high altitudes in the tropics.
Position in classification: Graphidaceae, Ostropales, Ostropomycetidae, Lecanoromycetes, Pezizomycotina, Ascomycota, Fungi.  

Locality data:

Ecology, geology: On Cladonia squamules. Soil WRB World Soil Reference W52B (Calcaric Leptosol i Calcaric Skeletic Leptic Regosol); Soil Taxonomy: Typic xerorthents, formed from chalk rocks and the deposits from their weathering; little edaphic development.
Altitude: 549 m.
Location: Guixera de la Creu, Argençola (Anoia).
Climate: Central Littoral Mediterranean (Tmm=13ºC, 538 mm)

Etymology of names:
Diploschistes (Norman, Conat. Praem. Gen. Lich.: 20, 1852) from the Greek δίπλοσ-σχίζω, meaning "doubly divided”) we interpret that the author means that the spores have transverse and longitudinal septa, since it is detailed in the description of the species (see attached description). The epithet muscorum, is the genitive plural of the Latin “mūscus”, meaning moss.

Source: Nyt magazin for naturvidenskaberne, 1853.
https://www.biodiversitylibrary.org/page/8152386#page/242/mode/1up

Source: Flora carniolica exhibens plantas Carnioliae indigenas et distributas in classes, genera, species, varietates, ordine linnaeano. Tom. II. ; Editio secunda aucta et reformata. http://bibdigital.rjb.csic.es/ing/Libro.php?Libro=983&Pagina=398

Bibliography:

Consortium of Lichen Herbaria https://lichenportal.org/portal/taxa/index.php?taxon=52885&clid=1079
Index Fungorum https://www.indexfungorum.org/names/NamesRecord.asp?RecordID=418987
Nimis P.L., 2024. ITALIC - The Information System on Italian Lichens. Version 7.0. University of Trieste, Dept. of Biology, (https://dryades.units.it/italic), accessed on YYYY, MM, DD. for all. All data are released under a CC BY-SA 4.0 licence.
https://italic.units.it/index.php?procedure=taxonpage&num=905