ITALIC 8.0

Arthonia caesiella Nyl.

Bot. Not.: 161, 1853.

Synonyms: Arthonia aphthoides Flagey nom. superfl.; Arthonia aphthosa Flagey; Arthonia galactiformis Flagey

Distribution: C - Sar (Sundin 1999).

Description: Thallus crustose, endosubstratic or thinly episubstratic, poorly delimited, pale grey to white. Apothecia arthonioid, emarginate, half-immersed to adnate, round to elongate and then simple with rounded ends, up to 1 mm long and up to 0.25 mm wide, black but usually blue-grey-pruinose. Proper exciple not developed; epithecium blackish, overlain by crystals (pruina), c. 15 μm high, K+ greenish: hymenium colourless to pale yellow, 30-50 μm high, I+ blue; paraphysoids coherent, thread-like, the apical cells hardly swollen: hypothecium pale ochraceous yellow, poorly delimited from hymenium, c. 20 μm high. Asci 8-spored, broadly clavate to subglobose, semi-fissitunicate, with a large apical dome, a distinct ocular chamber, and a K/I+ bluish ring-structure, Arthonia-type. Ascospores 1-septate, with unequal cells, hyaline, ovoid, rounded at one end, pointed at the other, 12-16 x 6-7 μm. Photobiont: trentepohlioid. Spot tests: thallus K+ pale yellow, C-, KC-, P-. Chemistry: unknown.

Note: a Mediterranean-Atlantic species found on smooth bark of deciduous and coniferous trees. Perhaps more widespread in the humid parts of Mediterranean Italy. It is included in the Italian red list of epiphytic lichens as “Critically Endangered” (Nascimbene & al. 2013c).

Growth form: Crustose

Substrata: bark

Photobiont: Trentepohlia

Reproductive strategy: mainly sexual

Pioneer species

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: absent

pH of the substrata:

1

2

3

4

5

(info)

Solar irradiation:

1

2

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4

5

(info)

Aridity:

1

2

3

4

5

(info)

Eutrophication:

1

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3

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5

(info)

Poleotolerance:

0

1

2

3

(info)

Altitudinal distribution:

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6

(info)

Predictive model

Index Fungorum GBIF

Harrie Sipman

Karpathos (Sipman & Raus 56349)
Identification not certain