ITALIC 8.0

Acarospora fusca B. de Lesd.

Rec. Lich. Dunkerque, 1, Suppl.: 100, 1914

Synonyms: Acarospora anomala H. Magn.

Distribution: N - TAA (Nascimbene & al. 2007b).

Description: Thallus crustose, episubstratic, minutely areolate, without a distinct prothallus, forming up to 1 cm wide patches. Areoles 0.2-0.9(-1.5) mm wide, 0,2.0,4 mm thick, contiguous, rounded to irregular, flat to usually slightly convex, deep brown to pale reddish brown, pale and ecorticate in lower part, epruinose. Epicortex lacking or <10 μm thick; cortex (10-)40-60 μm thick, the brown upper layer c. 10 μm thick, the lower layer colourless; algal layer 50-100 μm thick, even, continuous or rarely interrupted by <10 μm wide hyphal bundles, continuous beneath apothecia; medulla 100-250 μm thick, mixed with substrate particles. Apothecia lecanorine, 0.1-0.25(-0.6) mm across, rounded, 1-3(-4) per areole, immersed, with a reddish brown to dark brown, epruinose, usually flat, smooth or rough disc, and a usually paler brown, raised, smooth margin, the disc tending to become pseudogyrose when old. Proper exciple indistinct or expanding up to 60 μm around the disc, often forming an elevated margin concolorous with thallus; epithecium yellowish brown, c. 10 µm high; hymenium colourless, (85-)100-140(-160) µm high, the hymenial gel hemiamyloid, K/I+ light blue fading to light red; paraphyses 1-1.7 µm thick at mid-level, the apical cells cylindrical to clavate and up to 2.5 μm wide; subhymenium (20-)40-55 μm high, IKI+ blue; hypothecium 10-15 μm high. Asci 100-200-spored, clavate, the apical dome K/I-. Ascospores 1-celled, hyaline, narrowly ellipsoid to bacilliform, 3-5(-6) x (1-)1.5-1.7(-2) µm. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: a poorly known species of eutrophicated, dry and hard lignum and siliceous rocks, hitherto reported from several localities in Northern and Central Europe. For further details see Knudsen & al. (2021, 2021b). A dubious record from Campania by Garofalo & al. (1999) is not accepted here.

Growth form: Crustose

Substrata: lignum

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Poorly known taxon in need of further study

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: extremely rare

Oromediterranean belt: absent

Montane belt: extremely rare

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: absent

Humid mediterranean belt: absent

Dry mediterranean belt: absent

pH of the substrata:

1

2

3

4

5

(info)

Solar irradiation:

1

2

3

4

5

(info)

Aridity:

1

2

3

4

5

(info)

Eutrophication:

1

2

3

4

5

(info)

Poleotolerance:

0

1

2

3

(info)

Altitudinal distribution:

1

2

3

4

5

6

(info)

Predictive model

Index Fungorum GBIF

Source: Knudsen et al. 2017, Mycotaxon 132: 861

Neotype of Acarospora fusca (Schiefelbein 4446, NY): A, dispersed areoles of the thallus with solitary apothecia. B, areoles with mostly solitary apothecia forming a contiguous indeterminate crust. C, apothecia 1–(2–4) per areole in contiguous crust. D, vertical section of ascoma. Scale bars: A–C = 500 μm; D = 100 μm. (Reproduced from Knudsen et al. 2017, Mycotaxon 132: 861).GZU). C. Detail of the thallus with sharp edged areoles and immersed apothecia. – Scale bars: A, B = 1mm. C =500 μm.

Natural History Museum London - Source: https://mycoportal.org/portal/taxa/index.php?taxon=83801

Natural History Museum London - Source: https://mycoportal.org/portal/taxa/index.php?taxon=83801