ITALIC 8.0

Placynthium asperellum (Ach.) Trevis.

Sched. ad Lich. Ven. Exs.: nr. 98, 1869. Basionym: Collema asperellum Ach. - Lichenogr. Univ.: 629, 1810.

Synonyms: Catillaria subalpina Th. Fr.; Placynthium aspratile (Ach.) Henssen; Placynthium vrangianum Gyeln.; Pterygium asperellum (Ach.) Nyl.; Toninia asperella (Ach.) A. Massal.

Distribution: N - Lomb.

Description: Thallus crustose to subsquamulose, dark olive-brown to almost black, somehow glossy, forming 0.3-2.5 cm wide, irregular rosettes, the central parts densely papillose-granulose to isidiate, the margins usually with 1-1.5 mm long, 0.1-0.2 mm wide, irregularly radiating, separate, loosely attached and partly ascending, subcylindrical to subcanaliculate lobules, usually without a distinct prothallus. Thallus section with parallel, longitudinally arranged hyphae forming a cellular pattern. Apothecia lecideine, semi-immersed to sessile, up to 1 mm across, with a black, concave to finally convex disc and a thin, finally sometimes excluded proper margin. Proper exciple dark-brown; epithecium dark greenish brown; hymenium colourless, up to 100 µm high, amyloid; paraphyses sparingly branched, the apical cells thickened; hypothecium brownish. Asci (4-)8-spored, with an amyloid cap-like structure. Ascospores (1-)3-septate, hyaline, ellipsoid, 10-20(-25) x 4.5-7 µm. Pycnidia immersed, mostly marginal, subglobose, up to 0.15 mm wide. Conidia cylindrical or party dumbbell-shaped, hyaline, 4.5-8 x c. 1 µm. Photobiont cyanobacterial, Scytonema-like. Spot tests: all negative. Chemistry: without lichen substances.

Note: on moist calciferous and base-rich siliceous rocks in upland areas; the single record from the Italian Alps requires confirmation.

Growth form: Crustose

Substrata: rocks

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

Reproductive strategy: mainly asexual, by isidia, or isidia-like structures (e.g. schizidia)

Commonnes-rarity: (info)

Alpine belt: very rare

Subalpine belt: very rare

Oromediterranean belt: absent

Montane belt: absent

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

Index Fungorum GBIF

P.L. Nimis; Owner: Department of Life Sciences, University of Trieste

Herbarium: TSB (28410)
2003/03/12

Curtis Randall Björk – CC BY-SA 4.0

Northwest Territories, near MacKay Lake Date: 2011-08-02 On rock in periodically flooded depression, brushy tundra