Lecidea leprarioides

Thallus thin or endosubstratal, episubstratal granules (if present) to 0.1 µm diam.; surface whitish to green-grey or beige, dull, usually sorediate; soralia irregular, effuse, bursting through the uppermost layers of the substratum, forming a discontinuous leprose crust, soredia fine, 10–30 µm diam.; photobiont green, globose, to 10 µm diam. Apothecia rounded to flexuose or tuberculate, sessile with a constricted base, 0.2–0.85 (–1.2) mm diam.; disc dark grey to black, often whitish or bluish pruinose, weakly to strongly convex; margin lacking; exciple colourless to brown below, turquoise or greenish brown near the hymenium, N+ violet, laterally 25–50 µm thick, basally 30–60 µm thick, composed of branched and anastomosing radiating hyphae with 0.7–1 µm diam. unthickened apical lumina; epithecium greenish ochre to deep turquoise, composed of amorphous green pigment and ochre granules, 5–10 µm thick or streaking into the hymenium, N+ violet; hymenium colourless to pale green, 25–40 µm tall; paraphyses moderately branched and anastomosing, not thickened at the apex; subhymenium pale yellow to brown, poorly distinguishable from the hypothecium, ca 50 µm thick; hypothecium pale yellow to sordid reddish brown, 50–125 µm thick. Asci clavate, Bacidia-type with an I+ blue tholus and indistinct lighter blue tapering axial body, 8-spored. Ascospores colourless, aseptate, narrowly ellipsoidal, sometimes slightly curved, (6.5–) 8.2–9.8 (–11.5) × (2.5–) 2.7–3.4 (–4) µm. Pycnidia not seen. Thallus C–, K–, KC–, Pd–, UV– (pseudoplacodiolic acid).

The thallus morphologically resembles some thickly developed morphs of Ochrolechia microstictoides (thallus UV+ white) or pale variants of Lecanora expallens (thallus C+ orange). Related to L. turgidula, which has placodiolic acid and lacks soralia; see Schmull et al. (2011) for further details. A new genus within the Lecanoraceae would probably be justified.