ITALIC 8.0

Arthonia caerulescens (Almq.) R. Sant.

Flora, Regensburg 64, 21: 324, 1881.. Basionym: Arthonia apotheciorum subsp. caerulescens Almq. - K. svenska Vetensk-Akad. Handl., ny följd, 17, 6: 59, 1880.

Synonyms:

Distribution: S - Bas (Brackel & Puntillo 2023), Cal (Brackel & Puntillo 2023).

Description: Thallus inapparent, not lichenized, the hyphae developing inside the apothecia of Lecanora varia and related species. Apothecia arthonioid, black, rounded, 0.1-0.4 mm across, appearing as small, black dots on the apothecia of the host, then blackening the whole surface, Epithecium dark blue-green or brown with an olive tinge; hymenium 40-50 μm high, I+ blue; paraphysoids 1.5-2 μm thick at mid level, the apical cells with dark pigmented caps, 2-4 μm wide; hypothecium colourless to very pale brown. Asci 8-spored, broadly clavate to subglobose, semi-fissitunicate, with a large, non-amyloid apical dome, and a distinct ocular chamber, Arthonia-type. Ascospores 1-septate, slightly constricted at septum, hyaline, 10-12 x 4-6 µm. Photobiont absent. Spot tests: K-, C-, KC-, P-. Chemistry: without lichen substances.

Note: a lichenicolous fungus growing in the apothecia of Lecanora varia and related species; known among others from Spain, France, North Macedonia and Montenegro.

Growth form: Lichenicolous fungus

Substrata: lignum

Reproductive strategy: mainly sexual

paras Lecanora varia

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: very 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:

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

Herbarium samples

Index Fungorum GBIF

Source: J. Hafellner & M. Grube, The Lichenologist (2023), 55: 241–251

D, Arthonia caerulescens (Mayrhofer 641); habitus. Scales = 0.5 mm.