Umbilicaria decussata (Vill.) Zahlbr.

Cat. Lich. Univ, 8: 490, 1932. Basionym: Lichen decussatus Vill. - Hist. Plant. Dauphiné, 3: 964, 1789.
Synonyms: Gyrophora decussata (Vill.) Zahlbr.; Gyrophora discolor Th. Fr.; Gyrophora ptychophora (Nyl.) Nyl.; Gyrophora reticulata (Schaer.) Th. Fr.; Omphalodiscus decussatus (Vill.) Schol.; Umbilicaria ptychophora Nyl.; Umbilicaria reticulata (Schaer.) Nyl.
Distribution: N - Ven, TAA (Nascimbene & al. 2022), Lomb (Gheza 2019b), Piem (Isocrono & al. 2004, Isocrono & Piervittori 2008), VA (Piervittori & Isocrono 1999, Piervittori & al. 2004, Blisa & al. 2011, Matteucci & al. 2015c), Lig (Petrak 1960). S - Bas (Ravera & al. 2019b), Cal (TSB 3223)
Description: Thallus foliose-umbilicate, dorsiventral, monophyllous, thick and rigid, 2-4(-5) cm diam., attached by a very thick, short and compact central holdfast. Upper surface ash-grey, scabrous, with a white, reticulately ridged pattern, raised towards the center, adpressed or undulating, with a strongly wavy margins, the edges often down-turned. Lower surface black or dark brown in places, paler at margins, even or shallowly pitted, sometimes radiately folded around umbilicus, erhizinate. Thalloconidia covering the whole lower surface, 1-celled, spherical, dark brown to black, 7.3-8.5 µm diam. Upper cortex dark brown, palisade-plectenchymatous; medulla white, very loose under ridges; lower cortex scleroplectenchymatous. Apothecia very rare, black, stipitate, omphalodisc. Asci 8-spored, clavate, thick-walled, with an amyloid apical dome, Umbilicaria-type. Ascospores 1-celled hyaline, ellipsoid, 6-14 x 4-8 µm. Photobiont chlorococcoid. Spot tests: K-, C+ red or rarely C-, KC+ red or rarely KC-, P-. Chemistry: gyrophoric acid and small amounts of lecanoric acidk, especially in the medulla.
Note: an arctic-alpine to boreal-montane, circumpolar lichen found on steeply inclined to slightly rain-sheltered surfaces of wind-exposed siliceous rocks, reaching the nival belt in the Alps, and also reported from the mountains of Calabria.
Growth form: Foliose, umbilicate
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by conidia and thalloconidia
In underhangs rarely wetted by rain

Commonnes-rarity: (info)

Alpine belt: common
Subalpine belt: rather common
Oromediterranean belt: absent
Montane belt: rare
Submediterranean belt: absent
Padanian area: absent
Humid submediterranean belt: absent
Humid mediterranean belt: absent
Dry mediterranean belt: absent

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
Herbarium samples


Felix Schumm – CC BY-SA 4.0
[2763], Spanien, Sierra Nevada. Leg. Schumm 09.1979.



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (2553)
2001/12/05
detail of upper surface



Felix Schumm – CC BY-SA 4.0
[2763], Spanien, Sierra Nevada. Leg. Schumm 09.1979.



Felix Schumm – CC BY-SA 4.0
[2763], Spanien, Sierra Nevada. Leg. Schumm 09.1979.



Felix Schumm – CC BY-SA 4.0
[2763], Spanien, Sierra Nevada. Leg. Schumm 09.1979.


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Miris Castello - CC BY-SA 4.0; Owner: Department of Life Sciences - University of Trieste
Antarctica, Terra Nova Bay.
Herbarium: TSB - Antarctic Herbarium


Frey E. 1933. Cladoniaceae (unter Ausschluß ded Gattung Cladonia) und Umbilicariaceae. In: Rabenhrst’s Kryptogamenflora von Deutschland, Österreich und der Schweiz. 15: 1-208.
As U. reticulata



P.L. Nimis CC BY-SA 04
TSB 42319



P.L. Nimis CC BY-SA 04
TSB 42319



P.L. Nimis CC BY-SA 04
TSB 42319


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_U/Umbilicaria_decussata.htm
France, sur grès - Hautes-Alpes


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_U/Umbilicaria_decussata.htm
France, sur grès - Hautes-Alpes


Courtesy Danièle et Olivier Gonnet - Source: https://www.afl-lichenologie.fr/Photos_AFL/Photos_AFL_U/Umbilicaria_decussata.htm
France, sur grès - Hautes-Alpes


Ulrich Kirschbaum CC BY-SA 4.0 – Source: https://www.thm.de/lse/ulrich-kirschbaum/flechtenbilder
Austria: Alps.