ITALIC 8.0

Placynthium pannariellum (Nyl.) H. Magn.

Förteckning Skand. Växter, 4 (Lavar): 24, 1936.. Basionym: Pterygium pannariellum Nyl. - Not. Sällsk. Fauna Fl. Fenn. Förh., Ny Ser., 1: 236, 1859.

Synonyms:

Distribution:

Description: Thallus crustose-placodioid, dark olive-green to olive-brown, forming 2-3(-5) cm wide rosettes. Central parts breaking into irregularly shaped 1-2.5 mm wide and 0.4-0.8 mm thick areoles with isidioid, coralloid secondary lobules; marginal lobes convex, 0.5-1.5(-2) x 0.1-0.3 mm, 75-80(-120) µm thick, sparingly branched, finely striate, loosely attached on a distinct, bluish black prothallus. Upper cortex thin, olivaceous, of a single row of small cells, medulla thick, whitish, of densely aggregated, robust, somewhat elongated hyphae which are periclinally arranged or fan-shaped towards the surface; lower cortex dark, paraplectenchymatous, with dark rhizohyphae. Apothecia rare, lecideine, up to 1 mm across, with a brown-black disc and a distinctly paler proper margin. Epithecium blue green; hymenium colourless, up to 115 μm high; paraphyses septate, sparingly branched; hypothecium pale brown. Asci 8-spored, apically thickened, with an amyloid cap. Ascospores (2-)3-septate, hyaline, ellipsoid, 15-21 x (3-)4-6(-7) μm. Photobiont cyanobacterial, Scytonema-like. Spot tests: all negative. Chemistry: without lichen substances.

Note: on temporarily inundated siliceous rocks along streams and lake shores; widespread in Europe but much more common in Fennoscandia, with some records from the Alps, outside Italy; to be looked for in the Italian Alps.

Growth form: Crustose placodiomorph

Substrata: rocks

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

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

Periodically submerged (e.g. in creeks)

pH of the substrata:

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Solar irradiation:

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Aridity:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model

Index Fungorum GBIF

Curtis Randall Björk CC BY-SA 4.0

Northwest Territories, near MacKay Lake Date: 2012-06-03 On rock at lake shore in rocky tundra

Curtis Randall Björk – CC BY-SA 4.0

Northwest Territories, near MacKay Lake Date: 2012-06-03 On rock at lake shore in rocky tundra