Acarospora badiofusca (Nyl.) Th. Fr.

N. Acta Reg. Soc. Sci. Upsal., ser. 3, 3: 190, 1861. Basionym: Lecanora badiofusca Nyl. - Herb. Mus. Fenn.: 110, 1859.
Synonyms: Acarospora anziana H. Magn.; Sarcogyne acarosporoides Anzi
Distribution: N - Frl, TAA (Nascimbene & al. 2022), Lomb, Piem (TSB 33659), VA (Valcuvia 2000, Matteucci & al. 2015c), Emil (Fariselli & al. 2020), Lig (TSB 33438). C - Sar (Hafellner 1993, Rizzi & al. 2011, Cossu & al. 2015).
Description: Thallus crustose, episubstratic, pale to dark chestnut brown, sometimes grey-brown, areolate-subsquamulose, forming up to 8 cm wide patches, the areoles round or angular, sometimes indistinctly lobed, 0.7-3 mm across, up to 1 mm thick, contiguous to dispersed, flat to strongly convex, smooth or fissured and rugulose, epruinose; lower surface dark along the margins. Upper cortex paraplectenchymatous, the cells (3-)4-5(-6) µm wide, arranged in more or less vertical rows; algal layer continuous; medulla white. Apothecia 0.4-3 mm across, 1(-4) per squamule, when mature often larger than the corresponding areole, round to weakly angular, at first immersed, then subsessile, with an expanded, flat to slightly convex, smooth to rugose, black to dark reddish brown, matt disc, and a thin, prominent, concolorous proper margin. Proper exciple 15-20 µm wide; epithecium yellowish brown, 10-15 µm high; hymenium colourless, 60-90(-100) µm high, euamyloid, I+ persistently blue; paraphyses 2-3.5 µm thick at base, the apical cells to c. 5 µm wide; hypothecium colourless. Asci c. 200-spored, clavate, the apical dome K/I-. Ascospores 1-celled, hyaline, broadly ellipsoid to ellipsoid, 3-6 x 1.5-2.5(-3) µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.
Note: an arctic-alpine to boreal-montane, circumpolar species of base-rich or lime-containing siliceous rocks, such as mica-schists and calciferous sandstone, on faces wetted by rain, incl. stones near the ground in grasslands. Frequent only in the Alps, with optimum in the subalpine belt. The species does not belong to Acarospora s.str. (Westberg & al. 2015).
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: rather rare
Subalpine belt: rather common
Oromediterranean belt: very rare
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

Ulrich Kirschbaum CC BY-SA 4.0 - Source:
On rocks (gneiss).Austria: Alps.

P.L. Nimis CC BY-SA 04
TSB 9189

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (9189)

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (11370)

Magnusson A. H. (1935) Acarosporaceae, Thelocarpaceae. - In: Rabenhorst G. L.: Kryptogamen-Flora von Deutschland, Österreich, und der Schweiz-. 2nd- IX. Die Flechten. Abt. 5- 1. Gebr. Borntraeger. Leipzig, pp. 1-318. – Public Domain