ITALIC 8.0

Verrucaria fusca Pers.

in Ach., Lich. Univ.: 291, 1810

Synonyms: Verrucaria triglavensis Servít ?

Distribution: N - TAA (Nascimbene & al. 2022).

Description: Thallus crustose, thinly episubstratic, dark olive to brown-black, consisting of 0.1-0.25 mm wide flecks which are not subgelatinous when wet, often developed only around the perithecia, sometimes with a brown to black, fimbriate prothallus. Cortex consisting of a single layer of brown cells, most of the thallus thickness being occupied by the algal layer; medulla poorly developed. Perithecia black, hemispherically projecting, 0.25-0.3 mm wide, covered by a thin thalline layer at base. Involucrellum 30-50 μm thick laterally, becoming thicker downwards (up to 70 μm), reaching down to at least 2/3 of the perithecium, usually up to base-level, almost totally adpressed to exciple except at the very base, where the space between exciple and involucrellum is separated by a thin area of brown-walled cells; exciple subglobose to subpyriform, 0.2-0.3 mm across, the wall brown throughout; hamathecium of 15-25 μm long periphyses and periphysoids, interascal filaments absent; hymenial gel hemiamyloid, I+ red (I+ blue at very low concentrations of I), K/I+ blue. Asci 8-spored, clavate, I-, fissitunicate, the wall thickened above, with an ocular chamber, dehiscent by extrusion of an endotunica to form a delicate rostrum, Verrucaria-type. Ascospores 1-celled, hyaline, elongate-ellipsoid, 18-23(-27) x (6-)7-10(-13) μm. Photobiont chlorococcoid. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: an often misunderstood taxon, found both on calciferous and siliceous rocks, usually growing as a pioneer in rather sheltered situations, reported from several localities in Central Europe, incl. the Alps. Muchnik & Breuss (2015) attributed to this species a subgelatinous thallus, but according to Pykälä (in Oïhénart & al. 2018) the type of V. fusca has a non-subgelatinous thallus.

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: absent

Subalpine belt: very rare

Oromediterranean belt: absent

Montane belt: very rare

Submediterranean belt: absent

Padanian area: absent

Humid submediterranean belt: absent

Humid mediterranean belt: absent

Dry mediterranean belt: absent

pH of the substrata:

1

2

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4

5

(info)

Solar irradiation:

1

2

3

4

5

(info)

Aridity:

1

2

3

4

5

(info)

Eutrophication:

1

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3

4

5

(info)

Poleotolerance:

0

1

2

3

(info)

Altitudinal distribution:

1

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5

6

(info)

Predictive model

Source: Servit, M 1949: Nove nebo mene zname druhy lisejnikove celedi Verrucariaceae. Species Verrucariacearum (Lichenes) novae vel minus cognitae. - Sbornik Narodniho Musea v Praze 5(9): 1-51. Tab.1 - Public Domain

Zschacke, H. (1934) Epigloeaceae, Verrucariaceae und Dermatocarpaceae. In: Dr. L. Rabenhorst‘s Kryptogamen-Flora, Band 9, Abt. 1, Teil 1. Akademische Verlagsgesellschaft, Leipzig, 695 pp. - Public Domain