ITALIC 8.0

Placynthium tremniacum (A. Massal.) Jatta

Syll. Lich. Ital.: 38, 1900. Basionym: Racoblenna tremniaca A. Massal. - Ric. Auton. Lich. Crost.: 140, 1852.

Synonyms:

Distribution: N - Ven (Lazzarin 2000b), Lig (S- F155907).

Description: Thallus crustose to subsquamulose, shining brown, cracked-areolate and granulose-isidioid in central parts, forming up to 3 cm wide patches, with a very poorly developed prothallus. Apothecia rare, to 1 mm across, semi-immersed to sessile, with a dark brown disc and a thin, often finally excluded proper margin. Epithecium dark violaceous or dark greenish; hymenium colourless, amyloid; paraphyses distinctly septate, sparingly branched; subhymenium brownish. Asci 8-spored, apically thickened, with an amyloid cap. Ascospores mainly 1-septate, hyaline, ellipsoid, 10-15 x 4-6 µm. Pycnidia rare, dark-coloured, immersed, laminal, to 0.1 mm wide, with a greenish black ostiolum. Conidia 1-celled, hyaline bacilliform, 3-4 x c. 1 µm. Photobiont cyanobacterial, Scytonema-like. Spot tests: all negative. Chemistry: without lichen substances.

Note: the 1-septate spores, the thallus with somewhat stouter, more or less flat, minute squamules, and the less developed prothallus distinguish this rather poorly known species from P. nigrum. Czeika & Czeika (2007), however, consider this species as a synonym of the latter.

Growth form: Crustose

Substrata: rocks

Photobiont: cyanobacteria, filamentous (e.g. Nostoc, Scytonema)

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: very rare

Subalpine belt: very rare

Oromediterranean belt: very rare

Montane belt: very rare

Submediterranean belt: very rare

Padanian area: very rare

Humid submediterranean belt: very rare

Humid mediterranean belt: very rare

Dry mediterranean belt: very 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

Index Fungorum GBIF

Felix Schumm CC BY-SA 4.0

[12304], Griechenland, N-Samos, an der Straße von Agios Konstandinos nach Manolates, 37°47.229'N, 26°49.387'E, 205 m; feuchte, schattige Felswand in Bachnähe.
Leg. Schumm 02.05.2006, det. Schumm 2006.

Author: André Aptroot - Source: http://www.tropicallichens.net/ CC BY-SA-NC

Felix Schumm – CC BY-SA 4.0

[12304], Griechenland, N-Samos, an der Straße von Agios Konstandinos nach Manolates, 37°47.229'N, 26°49.387'E, 205 m; feuchte, schattige Felswand in Bachnähe. Leg. Schumm 02.05.2006, det. Schumm 2006.

Felix Schumm – CC BY-SA 4.0

[12304], Griechenland, N-Samos, an der Straße von Agios Konstandinos nach Manolates, 37°47.229'N, 26°49.387'E, 205 m; feuchte, schattige Felswand in Bachnähe. Leg. Schumm 02.05.2006, det. Schumm 2006.

Felix Schumm – CC BY-SA 4.0

[12304], Griechenland, N-Samos, an der Straße von Agios Konstandinos nach Manolates, 37°47.229'N, 26°49.387'E, 205 m; feuchte, schattige Felswand in Bachnähe. Leg. Schumm 02.05.2006, det. Schumm 2006.

Felix Schumm – CC BY-SA 4.0

[12304], Griechenland, N-Samos, an der Straße von Agios Konstandinos nach Manolates, 37°47.229'N, 26°49.387'E, 205 m; feuchte, schattige Felswand in Bachnähe. Leg. Schumm 02.05.2006, det. Schumm 2006.