Fuscidea lightfootii (Sm.) Coppins & P. James

Lichenologist, 10: 201, 1978. Basionym: Lichen lightfootii Sm. - in Smith & Sowerby, Engl. Bot., 21: tab. 1451, 1805
Synonyms: Biatora lightfootii (Sm.) Hepp; Biatora lightfootii f. commutata (Ach.) Zopf; Biatorina lightfootii (Sm.) Körb.; Catillaria lightfootii (Sm.) H. Olivier
Distribution:
Description: Thallus crustose, episubstratic, up to 0.9 mm thick, bright olive to dull grey-green, sometimes with a brownish tinge, finely to coarsely verrucose-areolate, sorediate, often delimited by a pale grey to dark brown prothalline line. Areoles often developing on a dark hypothallus, moderately to strongly convex, up to 0.3 mm wide, the apices often bursting into pale green or yellowish green, at first discrete, finally often confluent soralia, the soredia farinose, 15-30(-40) µm wide, sometimes gathered into 43-55 μm wide consoredia. Medulla up to 0•25 mm, thick, I-, with crystals visible under polarized light. Apothecia frequent, lecideine, 0.5-1 mm across, glossy, with a concave to slightly convex, dark grey-brown to black disc and a persistent, paler or concolorous, flexuose to sublobate proper margin. Proper exciple brown in outer part, paler within; epithecium brown; hymenium colourless to pale brown, 45-100 μm high, I-; paraphyses sparingly branched, 1.5-2.5 μm thick at mid-level, weakly coherent in water, more or less free in K, the apical cells clavate, to c. 5 µm wide, surrounded by a brown pigment; hypothecium colourless to straw-coloured. Asci 8-spored, clavate, developing at varying levels, with a thin external and internal K/I+ dark blue cap surrounded by a thick K/I+ pale blue apical cap, and with a K/I- apical tube in tholus, Fuscidea-type. Ascospores 1-celled or rarely 1-septate, hyaline, ellipsoid-cylindrical with obtuse ends, constricted in central part, (6-)8-10(-12) x (2.3-)3.5-4(-5) μm, quite thick-walled. Pycnidia inconspicuous, immersed. Conidia broadly ellipsoid to broadly pyriform, hyaline, aseptate, 1.5-2 x 1-1.5 µm. Photobiont chlorococcoid. Spot tests: medulla and soralia K-, C-, KC-, P-, UV+ bluish white. Chemistry: divaricatic acid.
Note: on the usually smooth bark of small twigs of various trees and shrubs in rather shaded and humid situations, often near bogs or streams; widespread in the Holarctic region, with a western tendency in Europe and a few scattered records from the Alps outside the Italian territory. To be looked for in the Italian Alps and in the Tyrrhenian ecoregion.
Growth form: Crustose
Substrata: bark
Photobiont: green algae other than Trentepohlia
Reproductive strategy: mainly asexual, by soredia, or soredia-like structures (e.g. blastidia)
Most common in areas with a humid-warm climate (e.g. most of Tyrrenian Italy)

pH of the substrata:

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Eutrophication:

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Poleotolerance:

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Altitudinal distribution:

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Predictive model
Herbarium samples

Harry Taylor; Owner: Natural History Museum London



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (32747)
2002/01/08



P.L. Nimis; Owner: Department of Life Sciences, University of Trieste
Herbarium: TSB (32747)
2002/01/08


Harry Taylor; Owner: Natural History Museum London