Magnusson, AH. 1939. Studies on Species of Lecanora, Mainly the Aspicilia gibbosa Group. Kongl. Svenska Vetenskapsakad. Handl. 17: 34-35.
Thallus covering large areas, continuous and uniform, plumbeous gray with a brown shade or +/- gray brown, C.U.C. 132, 232, 434, 514, thick and verrucose-areolate or thin with prominent fertile verrucae, areolae 0.8-1.3(1.6) mm large, 0.4-06 mm thick, +/- convex and uneven and separated by thin, irregular cracks, KOH-, no visible hypothallus.—Cortex developed laterally, 35-50 µ thick, exterior 16-20 µ +/- dark olive with perpendicular hyphae and oblong or subglobose lumina, 5-8 X 5 µ, the lower part transparent with indistinct, thick-walled lumina, 3-3.5(5) µ. Gonidia 8-12(17) µ, stratum not dense, about 50 µ, often +/- interrupted. Medulla opaque from air, lax, cellular with thin-walled lumina, 3-5(7) µ, lower part quite filled with oil drops, 5-8 µ large. Under surface somewhat (yellow)brownish, very densely constructed.
Apothecia solitary or two in the scattered verrucae or often 2-5 in the areolate thallus, De 45-80, immersed, disc 0.3-0.5(0.7) mm large, black, plane or concave, simple or often umbonate or gyrose, circular or irregular in shape, surrounded by a +/- obtuse and prominent, generally regular, gray or dark margin; approaching discs also separated by a similar margin.—Apothecia 200-300 µ deep. Exciple 150 µ broad at the surface, very dark olive, tapering down to a depth of 100-150 µ, at the base 20-30 µ, pale olive, I+ dark-blue up to the surface or indifferently coloured, upper hyphae of the exciple 5-6 µ thick, apparently thin-walled with +/- globose cells. The composed apothecia with several olive, +/- distinctly limited exciples in the disc and +/- large parts of it olive. Hypothecium 35-60 µ, opaque. Hymenium 120-150 µ high, I+ bluish green or reddish brown like the hypothecium; upper 20-30 µ +/- dark olive. Paraphyses conglutinated, not much branched, 1.7-2 µ thick, apices conglutinated also in KOH, submoniliform, 3.5-4 µ broad with 4.5-6 µ long, oblong joints, moderately constricted at the septa. Asci about 100 X 20 µ, clavate. Spores 8, (17)22-26 X (12)14-17 µ, broadly ellipsoid.
Pycnidia 200 X 200 µ, wall pale. Conidia 10-14 X 0.7 µ (acc. To NYL. 9-12 µ).
Habitat. On siliceous rocks in moist situation, near brooks or lakes.
Distribution. Finland, Russia, Sweden.
L. gyrodes is easily recognized when its apothecia are umbonate or gyrose, but also in a younger state on its high hymenium, large spores and perpendicular cortical hyphae. The thallus colour is generally +/- brown, the fertile verrucae very prominent with obtuse, often dark margin.