ITALIC 7.0

Verrucaria pachyderma Arnold

Verh. zool.-bot. Ges. Wien, 30: 146, 1880.

Synonyms: Verrucaria pissina Nyl.

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

Description: Thallus crustose, episubstratic, subgelatinous when wet, mostly continuous, 40-200 μm thick, smooth, dull or slightly glossy, dark grey-green to blackish, sometimes with a brownish tinge, rarely delimited by a thin dark prothallus. Cortex weakly defined, with a dull green to brown-black pigment (lacking in shade-forms); algal layer paraplectenchymatous, 50-80 μm thick; medulla poorly developed, with oil cells and sometimes with a dilute brown pigment, but without a black basal layer. Perithecia immersed in thallus, not or only slightly projecting, the apex visible as a grey to black dot or ring. Involucrellum reddish brown and K+ grey, from thin and adpressed to apex of exciple to conical and spreading, sometimes reaching base-level and laterally spreading, but rarely forming a black basal layer; exciple 0.16-0.2(-0.35) mm across, the wall colourless except around the ostiole; hamathecium of up to 20 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, ellipsoid to oblong-ellipsoid, (15-)17-22(-23.5) x 6-8(-9) μm, with a thin gelatinous perispore best visible in fresh material. Photobiont chlorococcoid, the cells arranged in vertical columns. Spot tests: K-, C-, KC-, P-, UV-. Chemistry: without lichen substances.

Note: a freshwater species of periodically submerged siliceous rocks in upland areas, also known from the British Isles, Scandinavia, and the Austrian and Swiss Alps. For further details see Orange (2013b).

Growth form: Crustose

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Periodically submerged (e.g. in creeks)

Commonnes-rarity: (info)

Alpine belt: extremely rare

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

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

Herbarium samples

Index Fungorum GBIF

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_V/Texte_V/Verrucaria_pachyderma.htm

France, 24/11/2011 - Asco, sous le lac d’Argent, alt. 2100 m - Corse

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_V/Texte_V/Verrucaria_pachyderma.htm

France, 24/11/2011 - Asco, sous le lac d’Argent, alt. 2100 m - Corse

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_V/Texte_V/Verrucaria_pachyderma.htm

France, 24/11/2011 - Asco, sous le lac d’Argent, alt. 2100 m - Corse

Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_V/Texte_V/Verrucaria_pachyderma.htm

France, 24/11/2011 - Asco, sous le lac d’Argent, alt. 2100 m - Corse

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