Aspicilia grisea Arnold

Ber. bayer. bot. Ges., 1: 62, 1891.
Synonyms: Aspicilia insolata (H. Magn.) Hav.; Lecanora grisea (Arnold) Lettau non Ach.; Lecanora griseolans Zahlbr.; Lecanora insolata H. Magn.
Distribution: N - Frl (Tretiach & Hafellner 2000), Lomb (Nascimbene & al. 2021).
Description: Thallus crustose, episubstratic, rather thin, continuous to rimose-areolate, grey, dark grey to almost black, sometimes delimited by a dark prothallus. Areoles flat to slightly convex, often rounded, 0.3-1 mm wide, bearing punctiform to orbicular, 0.2-0.8 mm wide, flat, yellowish white to ochre, rarely finally grey, often abraded soralia with farinose soredia (50-80 μm diam.), which sometimes develop shiny black tips and resemble isidia. Apothecia rare, lecanorine-aspicilioid, immersed in the thallus, 0.3-0.6 mm across, with a black, epruinose disc and a thin thalline margin; proper margin well-developed. Epithecium olive-green, N+ emerald green; hymenium colourless; paraphyses sparingly branched, moniliform in upper part, the apical cell to c. 3 μm wide. Asci 8-spored, clavate, the thin outer coat K/I+ blue, the wall and apical dome K/I-. Ascospores 1-celled, hyaline, ellipsoid, 18-26 x 9-15 μm. Photobiont chlorococcoid. Spot tests: thallus K+ yellow turning red (needle-like crystals), more rarely K+ persistently yellow, C-, KC-, P+ bright to golden yellow. Chemistry: norstictic acid, more rarely stictic acid as a major substance.
Note: a chemically variable species (see Roux & coll. 2014, 2020), found on siliceous rocks, sometimes also on pebbles, certainly more widespread in the Alps, but very much overlooked.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Pioneer species

Commonnes-rarity: (info)

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

pH of the substrata:


Solar irradiation:








Altitudinal distribution:


Predictive model
Herbarium samples

United States National Herbarium - Smithsonian – CC BY-SA NC Austria, Stiria, Montes Koralpe, in confinibus Stireae Carinthiaeque loco Hebalm dicto. Leg. J. Poelt