ITALIC 8.0

Arthonia granosa B. de Lesd.

Bull. Soc. Bot. France, 53: 518, 1906.

Synonyms:

Distribution: C - Laz (Ravera 2002b), Sar (Sundin 1999, Zedda 2002, Rizzi & al. 2011, Di Nuzzo & al. 2022). S - Camp (Ravera & al. 2018), Pugl (Nimis & Tretiach 1999), Si (CLU 16121).

Description: Thallus crustose, probably not lichenized, mostly endosubstratic and inapparent, or forming grey-white patches. Apothecia arthonioid, emarginate, immersed to erumpent, black but often grey-pruinose, round to slightly ellipsoid, 0.2-0.5 µm across, up to 100 µm tall. Proper exciple poorly developed; epithecium reddish brown, 10-20 µm high; hymenium colourless, 30-60 µm high, with granules, I+ red, K/I+ blue; paraphysoids 1-1.5 µm thick; hypothecium colourless, 5-10 µm high. Asci 8-spored, globose to broadly clavate, distinctly stipitate, semi-fissitunicate, with a large apical dome, a distinct ocular chamber, and an inconspicuous ring-structure in tholus, Arthonia-type, 35-55 x 30-45 µm. Ascospores 1-septate, not constricted at septum, hyaline, broadly ovoid, 17-25(-30) x 8-12 µm, without an epispore. Pycnidia up to 0.1 mm wide, unilocular. Conidia bacilliform, 3-5 x c. 1 µm. Photobiont probably absent. Spot tests: thallus K-, C-, KC-, P-, UV-. Chemistry: thallus without lichen substances.

Note: a Mediterranean-Atlantic epiphytic species restricted to coastal situations with humid maritime winds, generally on Juniperus, but also on Olea and Quercus ilex. Perhaps non-lichenised. It is included in the Italian red list of epiphytic lichens as “Vulnerable” (Nascimbene & al. 2013c).

Growth form: Crustose

Substrata: bark

Photobiont: Trentepohlia

Reproductive strategy: mainly sexual

Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)

Taxon bound to maritime-coastal situations

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: absent

Oromediterranean belt: absent

Montane belt: absent

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: absent

Humid mediterranean belt: very rare

Dry mediterranean belt: extremely rare

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

P.L. Nimis CC BY-SA 4.0

TSB 13225

Redinger, K. (1938) Arthoniaceae, Graphidaceae . In Kryptogamen-Flora von Deutschland, Österreich und der Schweiz. Band 9, 2 Abt., Part 1 (G. L. Rabenhorst, ed.): 181–404. Leipzig: Borntraeger