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

Apothecia: sessile or with a very short stalk, 0.160-.33(-0.7) mm high, typically occurring singly over host's thallus, shiny, epruinose, dark brown or to black stalk: 0-1 times as long as head, tapering abruptly into the capitulum, dark to pale brown or blackish, outer part with hyaline envelope to 35 µm thick; consisting of largely periclinally arranged, ruby red cells with strongly gelatinized, walls, 3-4 µm in diam. capitulum: 0.16-0.36(-0.5) mm wide, turbinate to +globose but often slightly irregular, shiny, black or dark brown; lower portion of exciple and upper portion of stalks: partially purplish to reddish brown in wet mount; mazaedium: black, extruding through constricted apex of exciple exciple: dark reddish brown or ruby red in section, K+ red, not sclerotized, 50-85 µm thick, consisting of largely periclinally oriented, intricately interwoven, branched hyphae 3-4 µm in diam.; upper part: slightly sclerotized, in the lower part, gelatinous, hyaline; hypothecium: hyaline, 35-50 µm high, consisting of isodiametric to irregular cells asci: cylindrical, 40-51 x 5-7 µm, with uniseriate spores, 8-spored ascospores: non-septate, dark brown, +globose to cuboid, mostly 3.4--6.9 x 4.5-7 µm, some slightly elongate to bullet-shaped and occupying terminal positions within asci; surface: with usually distinct ornamentation consisting of +distinct minute pores (easily misinterpreted as verrucae under the light microscope); when old, often with some irregular cracks; reticulate ornamentation often obscured by deep, dark brown to black pigmentation, giving the surface a papillate appearance; larger spores: irregularly sculptured; semi-mature spores: with thick, hyaline sheaths that become less evident with age Pycnidia: not seen Spot tests: exciple usually K+ intensely violet red Secondary metabolites: none detected but a reddish pigment present in the ascomata. Hosts: parasitic on Pertusaria (especially P. pertusa) or rarely Diploschistes, mainly on old trees (Quercus, Betula, Fagus, Fraxinus); Fink (1935) also reported it on Thelomma mammosum on rocks in California, but the identity of that material should be checked World distribution: Europe, Africa, and North America Sonoran distribution: southern California. Notes: See notes under S. leucopoda for a comparison with that species.