Lecanora horiza

General: Corticolous crustose lichen forming small patches or rosettes on tree and shrub bark, crowded with apothecia; thallus whitish with greenish hues, turning pale yellow with KOH (K+ pale yellow).

Apothecia: Sessile, disc-shaped, 0.4-1.8 mm diam., dark reddish-brown with a persistent whitish margin.

Asci: Clavate, 8-spored, 40-55 x 10-15 µm, spores biseriate to irregular, amyloid in Melzer's reagent.

Paraphyses: Filiform, hyaline, septate, 1.5-2.5 µm wide, simple or sparsely branched, terminal cell slightly swollen up to 3.5 µm and embedded in an amorphous reddish-brown pigment mass.

Ascospores: Ellipsoid, hyaline, unicellular, thin- to slightly thick-walled, 11-16 x 6-8 µm, lacking lipid guttules.