ITALIC 8.0

Acarospora saxonica H. Magn.

K. svenska Vetensk-Akad. Handl., Ser. III, 7, 4: 182, 1929

Synonyms:

Distribution: N - TAA (Rettig & al. 2023).

Description: Thallus crustose, episubstratic, areolate, grey-brown to dark brown, forming 1-2 cm wide patches, the areoles 0.5-0.8(-1) mm wide and 260-430 μm thick; lower side pale to blackish. Epicortex poorly developed or up to 20 μm thick; cortex paraplectenchymatous, (20-)30-40(-50) μm thick, brown in the upper 10-15 μm, colourless in lower part, with 2-5 μm wide cells; algal layer continuous, (40-)65-145 μm thick, the algal cells 10-15 μm wide; medulla up to 200 μm thick, with c. 2 μm thick hyphae. Apothecia lecanorine, 0.4-0-7 mm across, immersed in the areoles or projecting with the raised thalline margin, with a reddish brown to blackish, smooth to rough disc and an up to 60 μm wide thalline margin. Thalline exciple rich in algae; proper exciple poorly developed, 20-30 μm wide; epithecium brown, 15-25 μm high; hymenium colourless, 100-135(-150) μm high; paraphyses (1-)1.7-2(-3) μm thick at mid-level, the apical cells sometimes slightly wider; subhymenium 10-30 μm high, the hymenial gel hemiamyloid, K/I+ light blue fading to light red; hypothecium poorly developed, up to 10 μm high. Asci >100-spored, clavate, the apical dome K/I-, 80-100 x 12-17 μm. Ascospores 1-celled, hyaline, narrowly ellipsoid to almost bacilliform, 3-4 x 0.5-1 μm, almost resembling conidia. Pycnidia not known. Photobiont chlorococcoid. Spot tests: cortex and medulla K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: a species known from Germany, Austria and Switzerland, recently also reported from Italy (South Tyrol), found on siliceous rocks, including anthropogenous substrata such as glass, from 300 to c. 2000 m. For further details see Rettig & al. (2023).

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: extremely rare

Oromediterranean belt: absent

Montane belt: extremely rare

Submediterranean belt: very rare

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

Walter Obermayer - CC BY-SA 4.0

Specimen in GZU