ITALIC 8.0

Psorotichia diffracta (Nyl.) Forssell

N. Acta Reg. Soc. Sci. Upsal., 3, 13: 76, 1885. Basionym: Collema diffractum Nyl. - Mém. Soc. Imp. Sc. Nat. Cherbourg, 3: 198, 1855.

Synonyms: Collemopsis diffracta (Nyl.) Nyl.

Distribution: N - VG.

Description: Thallus crustose, black to dull dark green but most often densely blue-grey-pruinose, not granulose, areolate, homoiomerous, pseudoparenchymatous throughout, the areoles contiguous, 0.15-0.6 mm wide, flat to slightly convex. Apothecia lecanorine, semi-immersed, usually 1 or rarely 2 per areole, 0.2-0.5 mm across, with an initially punctiform, later expanded, concave, dark brown-red disc surrounded by a thick, smooth, pruinose thalline margin. Proper exciple poorly differentiated, 5-8 µm wide, not extending below the hypothecium; epithecium orange-brown, 15-20 µm high; hymenium colourless, 80-110 µm high, K/I+ blue; paraphyses branched and anastomosing, with cylindrical cells, only slightly constricted at septa, 2-3 µm thick; hypothecium colourless, 30-50 µm high. Asci 8-spored, cylindrical-clavate, with a very thin wall disintegrating or opening by apical ruptures, with an only indistinct amyloid cap, Lichina-type, Psorotichia subtype, 40-60 x 10-22 µm. Ascospores 1-celled, hyaline, ellipsoid, 10-16 x 5-9 µm. Pycnidia immersed, globose, unilocular or secondarily plurilocular, 50-65 µm across, with a colourless wall. Conidia globose or subglobose, 2-3 x 1-2 µm. Photobiont cyanobacterial, chroococcoid (Chroococcidiopsis), of a few cells measuring 3-10 x 3-8 µm, surrounded by a gelatinous sheath which is yellowish brown near the thallus surface. Spot tests: all negative. Chemistry: without lichen substances.

Note: on sun-exposed seepage tracks of calcareous rocks; overlooked, and perhaps more widespread.

Growth form: Crustose

Substrata: rocks

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

Reproductive strategy: mainly sexual

On otherwise dry surfaces with short periods of water seepage after rain

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: absent

Oromediterranean belt: absent

Montane belt: extremely rare

Submediterranean belt: 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

INDEX FUNGORUM GBIF

Source: Prieto M., Wedin M., Schultz M. 2024. Phylogeny, evolution and a re-classification of the Lichinomycetes. Studies in Mycology, 109: 595-655. - CC BY-NC-ND

Psorotichia diffracta, thallus pruinose, apothecia adnate with finally expanded discs (Groner 4157). Scale = 1 mm.

Matthias Schultz - source: http://www.biodiversity-plants.de/fbca002/fbca002_lichgal_calcic2.htm

Source: Prieto M., Wedin M., Schultz M. 2024. Phylogeny, evolution and a re-classification of the Lichinomycetes. Studies in Mycology, 109: 595-655. - CC BY-NC-ND

. Apothecium with thick, paraplectenchymatous thallus margin, hymenium with straight, septate paraphyses and juvenile asci in LPCB (Claudel & Harmand Lich. Gall. 485, B). Scale = 25 µm.