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

Notes: Because Spirographa so far is a monospecific genus, a generic description would simply recapitulate the specific description given below. The genus Spirographa was included in the Ostropales, family Odontotremataceae by Hawksworth and Sherwood (1982), together with the lichenicolous genera Lethariicola and Skyttea. Diederich and Etayo (2000) revised the genus Skyttea and suggested including it in the Helotiales; they tentatively included Spirographa in the same order, pending future studies. Diederich et al. (2002) revised the genus Lethariicola and considered it as a synonym of Odontotrema, the type of the family Odontotremataceae. A careful study of the ascomata of Spirographa (Diederich, unpubl.) confirms its cleistohymenial nature, putting the genus close to Odontotrema, as initially suggested by Hawksworth and Sherwood (1982). The excipular and epihymenial pigment is also the same as the pigment present in all Odontotrema species and in the monotypic genus Paralethariicola Calat., Etayo & Diederich. However, the periphysoid layer of the upper lateral exciple, that characterizes many species of the Odontotremataceae, is poorly developed or absent. As periphysoids were also poorly developed and hardly visible in some of the lichenicolous Odontotrema species studied by Diederich et al. (2002), it is considered of minor importance, and herewith it is proposed to keep Spirographa within the Odontotremataceae. Spirographa is distinguished from Odontotrema by its acicular, helicoid, 1-septate ascospores, poorly developed or absent periphyses, negative K/I-reactions of hymenium and asci, and the presence of a dark yellowish brown granulose layer covering the hymenium. Synonyms of Spirographa are Pleospilis Clem., Spilomela (Sacc.) Keissl., and Graphinella Zahlbr.