Buellia jugorum (Arnold) Arnold

Flora, 67: 588, 1884. Basionym: Buellia verruculosa var. jugorum Arnold - Verh. zool.-bot. Ges. Wien, 28: 295, 1879.
Synonyms:
Distribution: N - TAA (Scheidegger 1993). C - Sar (Scheidegger 1993).
Description: Thallus crustose, episubstratic, of scattered to adjacent areoles, yellowish white to pale yellow, with a smooth surface, the marginal areoles often slightly elongated and to 1.8 mm long, giving the thallus an almost placodioid appearance; medulla white, I-. Apothecia cryptolecanorine to zeorine, black, 0.3-0.6 mm across, innate to broadly sessile, with a flat to usually convex disc and a thin, finally often excluded proper margin. Proper exciple aethalea-type; epithecium greenish brown, N+ red; hymenium without oil droplets, 50-70 µm high, colourless in upper part, green and N+ red in lower part; hypothecium dark brown. Asci 8-spored, Bacidia-type. Ascospores 1-septate, slightly constricted at septum, oblong-ellipsoid, 11-15 x 6-8.5 µm, thin-walled throughout, Buellia-type, with a microrugulate ornamentation. Pycnidia black, immersed in the thallus. Conidia bacilliform, 6-9 µm long. Photobiont chlorococcoid. Spot tests: thallus K-, C+ persistently orange, KC+ yellow-orange, P-, UV+ orange. Chemistry: arthothelin.
Note: an arctic-alpine to boreal-montane, circumpolar species found on small siliceous pebbles in wind-exposed ridges, sometimes overgrowing other crustose lichens, mostly near and above treeline; probably more widespread in the Alps, certainly rarer in the high Mediterranean mountains.
Growth form: Crustose
Substrata: rocks
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly sexual

Commonnes-rarity: (info)

Alpine belt: rather rare
Subalpine belt: extremely rare
Oromediterranean belt: rare
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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Poleotolerance:

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Altitudinal distribution:

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Einar Timdal - Source: http://www.nhm2.uio.no/botanisk/lav/Photo_Gallery/Buellia/jugorum_G=Iceland+Snaefellsnessysla_D=20050721_H=O-L138144_O=E-Timdal_C=ET_I=DSCN0265.JPG