Arctoparmelia centrifuga (L.) Hale

Mycotaxon 25: 252 (1986).

Basionym: Lichen centrifugus L., Sp. Pl. 2: 1142 (1753).


Protolog: Data lacking.

Type locality: Sweden? (LINN 1273.58, upper specimen lectotype, Jørgensen et al., Bot. J. Linn. Soc. 115: 373 (1994).

Barcode: Available. Data lacking.

Coordinates: Data lacking.

Thallus: foliose, closely adnate, orbicular, forming concentric circles to almost one metre diameter. Upper surface glossy, yellowish to green-yellow, in central parts darker, greyish, occasionally totally without yellowish tinge. Lower surface pale to whitish brown with sparse blackish rhizines. Lobes 1 - 2 mm wide. Apothecia common in the central parts, to 5 mm diameter; disc reddish brown. Spores ellipsoid, 8 - 14 / 4.5 - 6 µm. Pycnidia frequent, laminal and immersed. Conidia slightly dumbbell-shaped, 5-7 / 1 µm (Moberg & Thell 2011: 20).

Photobiont: Trebouxia.

Race I: Cortex C-, K+ yellow, KC-, PD-; atranorin and usnic acid. Medulla C-, K-, KC+ red, PD-, atranorin and alectoronic acid. Usnic acid is occasionally absent, and 3 - 4 unidentified additional compounds (three fatty acids) are usually present (Moberg & Thell 2011: 20).
Race II: Usnic acid lacking.

Ecology: Saxicolous, usually growing on large boulders, rarely lignicolous and corticolous (Moberg & Thell 2011: 20).

Molecular data: Genbank

Distribution: Arctic boreal worldwide. Very common in northern Fennoscandia, rarer in the south. It has not been refound at its old localities in Skane. Database

Note: A conspicuous ashy grey, usnic acid-deficient form has sometimes been recognized as a distinct species, Arctoparmelia aleuritica (Hale 1986, Clayden 1992, Moberg & Thell 2011: 20).