ITALIC 7.0

Arctoparmelia centrifuga (L.) Hale

Mycotaxon, 25: 252, 1986. Basionym: Lichen centrifugus L. - Sp. Pl., 2: 1142, 1753.

Synonyms: Parmelia centrifuga (L.) Ach.

Distribution: N - Ven, Piem.

Description: Thallus foliose, closely adnate, dying in the center and forming concentric rings which can reach almost 1 m in diameter. Lobes irregularly branched, flat to slightly convex, 1-2 mm broad, with pointed tips. Upper surface greenish yellow or partly whitish green, darkening toward center. Lower surface whitish or pale brown, with sparse, brown to blackish rhizines. Upper cortex of tightly packed, anticlinally oriented hyphae, with a pored epicortex, the cell walls with Cetraria-type lichenan; medulla white, not amyloid; lower cortex appearing velvety due to minutely papillose hyphae. Apothecia lecanorine, laminal, adnate, to 5 mm across, with a reddish brown to dark brown disc and an entire to crenulate, sometimes inflexed thalline margin. Epithecium brownish; hypothecium and hymenium colourless; hymenium I+ blue. Asci 8-spored, thick-walled, the apex I+ blue with a wide, divergent axial body, Lecanora-type. Ascospores 1-celled, hyaline, ellipsoid, 8-14 x 4.5-6 µm. Pycnidia frequent, laminal immersed. Conidia slightly dumbbell-shaped 5-7 x c. 1 µm. Photobiont chlorococcoid. Spot tests: cortex K+ yellow, C-, KC-, P-; medulla K-, KC+ red, P-. Chemistry: cortex with usnic acid and atranorin; medulla with alectoronic acid.

Note: an arctic-alpine lichen of exposed siliceous rocks near or above treeline, certainly very rare in the Alps (Austria). Italian records need confirmation (see Nimis 1993: 490).

Growth form: Foliose, narrow lobed

Substrata: rocks

Photobiont: green algae other than Trentepohlia

Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: extremely rare

Subalpine belt: extremely rare

Oromediterranean belt: absent

Montane belt: absent

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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5

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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