Xanthoria mediterranea Giralt, Nimis & Poelt

J. Hattori Bot. Lab., 74: 275, 1993.
Synonyms: Physcia parietina var. isidioidea Beltr.?; Xanthoria isidioidea (Beltr.) Szatala?
Distribution: N - Frl (TSB 21653), Lig (Giordani & al. 2009). C - Laz (TSB 5359), Abr (Eichenberger 2007), Mol (Garofalo & al. 1999, Nimis & Tretiach 1999, Caporale & al. 2008), Sar (Rizzi & al. 2011). S - Camp (Garofalo & al. 1999, Aprile & al. 2003b, Nimis & Tretiach 2004), Pugl (Garofalo & al. 1999, Nimis & Tretiach 1999, Durini & Medagli 2002), Bas (Nimis & Tretiach 1999), Cal (Puntillo 1996), Si (Nimis & al. 1996b).
Description: Thallus foliose, orange to orange-yellow, rather firmly attached, forming 2-3 cm wide, orbicular rosettes which soon tend to coalesce into irregular, much larger thalli. Lobes 2-3 mm wide, flat, rounded at apex, with first wart-like, then clavate to cylindrical, c. 80-200 µm thick, simple to sparingly branched, terete or slightly flattened isidia; lower surface pale, attached to the rock by irregular, coarse hapters. Upper and lower cortex paraplechtenchymatous, the former 10-20 µm thick, the latter 15-20 µm thick, the cells 4-7 µm in diam.; medulla white, rather lax, most hyphae running parallel to the substrate. Apothecia very rare, lecanorine/zeorine, up to 3 mm across, with a concave, deep orange disc and a usually somewhat paler, smooth to isidiate thalline margin. Epithecium brownish-orange, K+ red, hymenium and hypothecium colourless; paraphyses simple or sparingly branched, septate, swollen at tips. Asci 8-spored, clavate, functionally unitunicate, apically thickened with a broad internal beak, the inner part of apex and external cap I+ blue, Teloschistes-type. Ascospores 2-celled, polarilocular, hyaline, ellipsoid, 12-16 x 6-8 µm, the equatorial thickening (“septum”) 4-5 µm. Pycnidia immersed into dark orange warts. Conidia hyaline, ellipsoid, 2-3 x 1.2-1.8 µm. Photobiont: chlorococcoid. Spot tests: cortex K+ dark red, C-, KC-, P-, UV+ intensely orange-red. Chemistry: thallus and apothecia with unidentified anthraquinones, but most probably with parietin (major), fallacinal, emodin, teloschistin and parietinic acid.
Note: a mainly Mediterranean species found on the top of isolated calcareous boulders, often together with X. calcicola, and with a similar ecology, but with a narrower altitudinal range.
Growth form: Foliose, broad lobed
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by isidia, or isidia-like structures (e.g. schizidia)

Commonnes-rarity: (info)

Alpine belt: absent
Subalpine belt: absent
Oromediterranean belt: absent
Montane belt: absent
Submediterranean belt: extremely rare
Padanian area: absent
Humid submediterranean belt: extremely rare
Humid mediterranean belt: very rare
Dry mediterranean belt: rare

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
Index Fungorum GBIF

Manuel Gil
Spain, Canary Islands, Lanzarote, Vega de Temuime



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (7566)
2001/12/03
detail of isidia



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (7566)
2001/12/03


Pier Luigi Nimis - CC BY-SA 4.0
Herbarium: TSB 7966


Pier Luigi Nimis - CC BY-SA 4.0
Herbarium: TSB 7966


Pier Luigi Nimis - CC BY-SA 4.0
Herbarium: TSB 7966


Leif Stridvall - Courtesy: Anita Stridvall - Source: http://www.stridvall.se/lichens/gallery/
as X. isidioidea