Fuscidea lightfootii  

Thallus bright olive to dull grey-green or suffused brownish, finely to coarsely verrucose-areolate, occasionally ± papillate, the strongly convex areoles up to 300 µm diam., usually sorediate. Soralia pale or yellowish green, becoming confluent, often bursting from the apices of areoles, granular, sometimes farinose. Soredia 15-30 (-40) μm diam. Prothallus pale grey to dark brown. Photobiont chlorococcoid (? Chlorella); at least partly in clusters of 2-4 daughter cells resulting from binary fission, often not round but asymmetrical with one flattened side.
Anamorph: conidiomata pycnidia, inconspicuous, immersed in areoles. Conidia 1.5-2 x 1-1.5 µm, broadly ellipsoidal to broadly pyriform, hyaline, aseptate.
Teleomorph: ascomata apothecia, 0.5-1 mm diam., frequent, dark grey-brown to black, shining. True exciple paler or concolorous, flexuose, irregular or sublobate, at times surrounded by thalline granules and appearing to have a thalline exciple. Epithecium brown. Hymenium hyaline to pale brownish, I–. Hypothecium pale straw-yellow. Interascal tissue of paraphyses 1.5-2 μm diam., sparsely branched, weakly conglutinated in water, especially at the apices, becoming ± free in K, a brown pigment surrounding the 1-2 uppermost cells; upper cell clavate, to ca 5 μm diam. Asci subcylindrical to clavate, with a thin external and internal K/I+ dark blue cap surrounded by a thick K/I+ pale blue, gelatinous layer but a K/I– apical tube in the tholus, 8-spored. Ascospores 8-11 × 3.5-4.5 μm, cylindric-ellipsoidal with obtuse ends, constricted in the mid region, quite thick-walled, hyaline, smooth, without a perispore, gelatinous sheath or appendages.
Chemistry: thallus UV+ bluish white (divaricatic acid).