Thallus usually forming extensive, coalescing patches, greyish, light yellowish brown or pale to dark brownish, weakly areolate, usually divided into secondary verrucae. Verrucae bullate, dispersed, becoming crowded, papillate to subsquamulose, roundish to ellipsoidal, often irregularly constricted at the base. Upper surface matt to somewhat shining, upper cortex paraplectenchymatous. Prothallus brown to black.
Anamorph: conidiomata pycnidia, numerous, immersed, 75–150 µm diam., brown near the ostiole. Conidia 14-24 x ca 0.8 µm, filiform, slightly to strongly curved.
Teleomorph: ascomata apothecia, 0·5–1·0 (–1·4) mm diam., sessile to almost substipitate. Disc plane to slightly concave, red-brown to dark brown, not pruinose. Thalline exciple entire or more often flexuous or crenulate, 0·1–0·2 mm wide, concolorous with the thallus, becoming excluded, the outer edge anatomically distinctive, similar to cortex of the papillae, with a hyaline amorphous layer above a single outer layer of isodiametric cells with brown-pigmented, thickened walls, within composed of compact, short-celled, somewhat radiating pseudoparenchyma intermixed with photobiont cells. Hymenium 40–70 µm high. Epithecium reddish brown to dark brown. Interascal tissue of paraphyses, slightly swollen and short-celled towards the apices, sometimes almost sub-moniliform. Asci cylindric-clavate to clavate, 8-spored. Ascospores 10–15 (–18) x (3–) 4–5 (–5·5) µm, cylindrical to ellipsodal, (0–) 1–septate, hyaline, smooth and thin-walled, without an epispore, gelatinous sheath or appendages.
Chemistry: no lichen substances detected.
Assessed by Woods & Coppins as of Least Concern, but listed as Nationally Rare. Some older records of Lecania aipospila are likely to belong here.
Compared with Lecania aipospila, L. fructigena has smaller, densely crowded and papillate thallus warts and lacks terpenes.
Records are scattered along the west coast of Britain, and maritime localities in east central Scotland. BLS map here.
On weakly basic or on siliceous rocks subject to bird-manuring, and seepage tracks, sometimes close to the high tide mark.