Xanthoria parietina forme lignicole sur bois travaillé.
Thallus foliose, rosette-shaped, tightly appressed to the substratum, in general 2-3 cm diam., but potentially forming colonies, 5-10 cm across, lobes markedly indented or digitate at first, but some well developed and old specimen may have larger and regular lobes, soredia, isidia and blastids absent, overall colour grey-greenish, grey-yellowish when shaded, turning to yellow when well lit. Apothecia distribution pattern typical, clustered in specific zones close to the lobes margins, markedly sessile or even shortly stipitate, 2-4 mm diam., disc concave to flat, cup-shaped, pale orage, pale yellow, exciple well developed, erect and upturned toward the disc, smooth to slightly uneven or crenulate, whitish, pale grey-yellowish. Ascospores simple, ellipsoid, 11-16 x 6-8 µm. Thallus : K+ purple. This morph, rather common in our prospection area, grows near the seashore on rather nutrient-rich horizontal surfaces of bare wood (benches, tables, poles, wood ship wrecks, etc.). N.B. This morph resemble to some taxa belonging to the Xanthoria candelaria group but the latter have blastids on lobes and are little fertile, and to the less luxuriant Xanthoria parietina lignicolous foreshore wood poles form.