Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.

Apothecia: dispersed on the host thallus, immersed to superficial, black, (150-)200-400(-500) µm in diam. gin: in opened ascomata: 80-140 µm thick, with numerous narrow and deep fissures; excipular hairs: macroscopically not visible; ascomatal pore: mostly 0-20(-30) µm in diam., in some specimens up to 100 µm wide exciple: in central and outer parts dark red to black (red color sometimes obscured and difficult to observe), K+ aeruginose green, in inner parts brown, K+ purplish violet (reaction very distinct, quicker, but much weaker than the aeruginose one), laterally 30-45 µm wide, basally 50-130 µm wide; excipular hairs: hyaline to pale brown, often with one of the excipular pigments and then K+ purplish-violet or K+ aeruginose green, non-septate, smooth or apically slightly roughened, 35-45(-50) x 2-3 µm epihymenium: pale brown, K- or K+ pale purplish-violet hymenium: hyaline, 55-60 µm tall; paraphyses: septate, simple, 1.7-2 µm thick; subhymenium: hyaline to pale brown, 5-10 µm thick asci: cylindrical, unitunicate, wall laterally thin, apically thickened, (5-)8-spored, 40-60 x 5-8 µm; ascogenous hyphae: with croziers ascospores: hyaline, simple, ellipsoid to narrowly ellipsoid, 6-10.5 x 3-4 µm. Hosts: on thallus of corticolous Pertusaria species, including P. cf. coccodes, P. heterochroa and P. cf. santamonicae, not visibly damaging the host World distribution: Europe (Mallorca) and North America (Mexico and U.S.A.) Sonoran distribution: southern California and Baja California. Notes: Diederich and Etayo (2000) recognized three Skyttea-species with a red, K+ aeruginose excipular pigment