Magnusson, A.H. 1939. Studies on species of Lecanora, mainly the Aspicilia gibbosa group. Kungl. Svenska Vetenskapsakademiens Handlingar. 17:1-182.
Thallus only few cm in diam., determinate with indistinctly radiating circumference, bluish-gray white or pale plumbeous, C.U.C. 680, verrucose-areolate, areolae 0.5-0.7(1) mm wide, 0.3-0.5 mm thick, irregularly convex, separated by thin cracks, the marginal areolae +/- lobe-wise lengthened, much thinner, less convex, apices of the uttermost areolae +/- darkened, thallus surface on the whole as if thinly bluish-gray pruinose, externally KOH-.
No strata seen in the quite opaque, gray or white thallus sections but granules gradually dissolving in HCl and thallus transparent. Cortex 15-25 (35) µ thick, like the 50-80 µ thick gonidial stratum still somewhat obscured in HCl, becoming intensely yellow in KOH and then transparent, apices of cortical hyphae yellowish brown, 5-6 µ. Gonidia 10-15 µ. Medulla with mainly perpendicular hyphae, in HCl 3.5-4.5 µ, +/- branched, thick-walled, cells rounded or stretched, also medulla in KOH with pale yellow mist.
Apothecia quite immersed, towards the centre De 150-200, discs solitary or 2(3) in each areola, punctiform in the younger parts, +/- plane or concave at the centre, 0.2-0.4 (0.5) mm broad, deeply immersed, generally thinly pruinose, surrounded by the turgid, prominent, sometimes irregular part of the verruca.
Apothecia only 110-150 µ deep with much granules. Exciple +/- distinct at the base, refracting, 12-15 µ, laterally and at the surface indistinct, I+ dark blue at once. Hypothecium 20-30 µ, hyphae intricate, 2-2.5 µ (HCl +), I+ dark blue. Hymenium 70-80 µ high, I+ dark greenish-blue; upper 10 µ (reddish-) brown. Paraphyses in HCl 2 µ thick, K+ discrete, moniliform, much branched, uppermost joints subglobose or broadly ellipsoid, epithecium K+ reddish brown with a +/- yellow mist. Asci not numerous, about 50 X 20-25 µ, swollen clavate. Spores shrunk, indistinct, in KOH 12-15(17) X 7.5-8.5 µ, ellipsoid.
Pycnoconidia 16-18 X 0.6 µ, straight, according to STEINER (loc. cit.) 14-18(19) µ.
Habitat. On calciferous stone or serpentine.
Distribution. Austria. Pinzgau A. SAUTER (U., W., type) called Urc. pelobotrya by SAUTER; part of it sent to TH. FRIES by KREMPELHUBER. – Italy. Lombardia: Sondrio, >>Sul serpentine nell’alpe de la Rocca>> ANZI (Paris, hb. HUE), stone HCl-.
L. verruculosa is characterized by the positive K-reaction against L. permutata, by the thin cortex, the rather distinctly moniliform paraphyses and the bluish shade of the rather thick thallus. L. Henrici B. DE LESD. is very nearly related or perhaps identifical but there seems to be a distinct difference at least in the much longer conidia.
There has been, and is still, some doubt as to the interpreting of the name verruculosa.Although not being fully convinced that STEINER is right when attributing the name to SAUTER’s specimen I prefer to adopt it instead of creating new names.