Diplotomma glaucoatrum (Nyl.) Cl. Roux

Bull. Soc. linn. Provence, 66: 92, 2015. Basionym: Lecidea glaucoatra Nyl. - Flora, 56: 198, 1873.
Synonyms: Buellia glaucoatra (Nyl.) Clauzade
Distribution: C - Tosc (Ravera & al. 2022), Sar (B-Leg. H. Sipman nr. 24073).
Description: Thallus crustose, episubstratic, rather thick, verrucose-areolate, pale glaucous grey to ochraceous grey, rarely delimited by a thin, dark prothalline line. Medulla white, I-. Apothecia black, lecideine, 0.3-0.8(-1) mm across, initially immersed, then slightly prominent, with a black, flat to convex, epruinose or faintly pruinose disc, and a thin, finally excluded proper margin. Proper exciple brown in outer part, colourless to pale brown in inner part, of radiating hyphae; epithecium brown; hymenium colourless, K/I+ blue; paraphyses simple, c. 2 μm thick at mid-level, the apical cells up to 3 μm wide; hypothecium brown. Asci 8-spored, clavate, Bacidia-type. Ascospores at first 3-septate, then submuriform, brown, ellipsoid, 12-22 x 7-11 µm. Photobiont chlorococcoid. Spot tests: K-, C- KC-, P-, UV-. Chemistry: without lichen substances.
Note: a saxicolous taxon of the D. alboatrum-group with a grey-white, verrucose to areolate thallus, found on various types of rocks near the seashore, widely distributed along the Atlantic and Mediterranean coasts of Europe. According to Roux & coll. (2014) this is a good species, differing from D. alboatrum in morphological characters and in the ecology; the Italian sample, identified by H. Sipman, was collected at Capo Falcone (Sassari), on siliceous schist boulders and outcrops, on steep slopes with garrigue at seashore, just above highwater level.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual
Taxon bound to maritime-coastal situations

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: absent
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: absent
Humid mediterranean belt: very rare
Dry mediterranean belt: very rare

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

S. Poumarat - Source: http://mycologie.catalogne.free.fr/lichens.htm