Diploschistes gypsaceus

Diploschistes gypsaceus (Ach.) Zahlbr.

Thallus crustose, white-grey, episubstratic, farinose.
Reproduction: Apothecia 2-5 mm; semi-immersed in the thallus; disc blackish pruinose with a raised thalline margin. Asci 4-spored. Spores muriform, brown, ellipsoid, 25-40 x 10-17 µm; transverse septa 4-7, longitudinal septa 1-2.
Photobiont: Chlorococcoid.
Spot tests: C+ red, K-, KC-, P-, UV-.
Chemistry: Lecanoric acids. 

Habitat: On calcareous rocks, found in fissures, on rain-sheltered surfaces. 
Distribution: Abundant in areas with a Mediterranean climate or dry temperate.
Position in classification: Graphidaceae, Ostropales, Ostropomycetidae, Lecanoromycetes, Pezizomycotina, Ascomycota, Fungi.

Locality data:
Ecology, geology: On calcareous conglomerates, in fissures.
Altitude: 760 m
Location: San Joan del Codolar, Camí de la Llissera. Cornudella de Montsant. Parc Natural de la Serra de Montsant (Priorat)
Climate: South Pre-Littoral Mediterranean (Tmm=12,7ºC, rainfall 615 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 gypsaceus, from the Latin gypsum, from the Greek γύψος, meaning chalk.

Bibliography:
Consortium of Lichen Herbaria 
Index Fungorum
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 2024/12/22 All data are released under a CC BY-SA 4.0 licence.