Herteliana gagei  

Thallus crustose, superficial, to 30 cm diam., creamy white, pale greenish white or glaucous to bluish green (duck egg colour), thick, continuous or rimose-cracked. Prothallus ± distinct, black, delimiting. Photobiont chlorococcoid.
Anamorph: conidiomata pycnidia, immersed, black. Conidia 17-20 × ca 1 μm, narrow, falcate, simple, hyaline, arising singly from the apices of the conidiogenous cells.
Teleomorph: ascomata apothecia, 500-700 µm diam., initially immersed, becoming sessile by rupturing the thallus surface which remains as a rim round the exciple, red-brown. Thalline exciple absent. True exciple persistent, pseudoparenchymatous, pale brown to orange. Disc convex, ranging from shallowly convex to ± tuberculate. Epithecium orange-brown, ± granular. Hymenium ± hyaline to pale orange, I+ blue. Hypothecium well developed, root-like, ± hyaline to yellow- or orange-brown. Interascal tissue of simple or sparsely branched paraphyses 1-2 µm diam., the apices swollen to 3-4.5 µm diam. Asci elongate-clavate, with a thickened K/I+ blue tholus including a less intensely staining ocular chamber, 8-spored. Ascospores (16-) 18-22 (-25) × 8-10 (-11) μm, broadly fusiform, somewhat pointed at the apices, aseptate, hyaline, smooth, lacking an epispore, gelatinous sheath and appendages.
Chemistry: thallus C–, K+ yellow, KC+ yellow, Pd– or Pd+ yellow (atranorin, confluentic acid, 2 unidentified substances).