Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2007. Lichen Flora of the Greater Sonoran Desert Region. Vol 3.
Life habit: lichenized Thallus: crustose, effuse, continuous to rimose; in section, up to 120 µm thick surface: white, smooth or slightly farinose Ascomata: 0.3-2 x 0.1-0.3 mm, adnate without constricted base, scattered or aggregated, straight to flexuous, simple or slightly branched, with a slit-line disc, becoming sometimes widely exposed, epruinose exciple: closed, but open when immature, 20-60 µm laterally, 0-60 µm wide at base, brown-black, K+ slightly olivaceous hymenium: hyaline, inspersed with numerous oil droplets, 90-160 µm, I+ reddish, K/I+ pale blue; subhymenium: to 50 µm, pale brown; paraphysoids to 1.5 µm wide asci: clavate to cylindrical-clavate, 65-70 x 16-18 µm (Varia-type) ascospores: from oblong-ovoid to elongate-fusiform, the upper apex rounded and narrowing to the lower end, 21-24(-26) x 4-6 µm, 6-7-septate, dark brown granulose already when young due to pigmentation in the perispore and the spore wall, slightly constricted at one or more septa, thick walled, the cells ± lenticular with thickened septa and with a thin gelatinous sheath (Parasitica-type) Conidia: 10-17 x 1 µm, curved Spot tests: thallus K-, C+ reddish or C-, KC-, P- Secondary metabolites: unidentified substance (arthoniaic acid?) of RF 3,3,2, gray. Substrate and ecology: on dry, rough bark, in coastal shrub community; on Euphorbia misera, Harfordia fruticosa, Fouquieria World and Sonoran distribution: Baja California and Baja California Sur. Notes: Opegrapha corinnae is unique within the well known species of Opegrapha by its 6-7-septate ascospores becoming dark brown very soon and the hymenium inspersed with numerous oil droplets. Leciographa A. Mas-sal. and Sclerographa (Vainio) Zahlbr. are two synonyms of Opegrapha formerly characterized by their brown ascospores. Leciographa was described by Massalongo (1854) based on the species L. parasitica A. Massal. [= Opegrapha parasitica (A. Massal.) H. Olivier]. Sclerographa was introduced as a section of Opegrapha by Vainio (1890), including O. quinqueseptata Vain. and O. sordidescens Vainio. Later, this section was treated as an independent genus by Zahlbruckner (1926). Examination of the type material of O. quinqueseptata and O. sordidescens, has shown that the ascospores of these taxa are brown, but hyaline when young. The pigmentation occurs by accumulation of granules in the perispore, and not in the spore wall. In O. corinnae, the pigmentation occurs in the perispore and in the spore wall, and rarely we can find very young ±hyaline ascospores. A brown pigment in ascospore walls has also been mentioned by Coppins (1987) in O. pulvinata (see under that species). According to Upreti and Singh (1987), spore coloration alone is not sufficient to segregate supraspecific taxa. Opegrapha corinnae is named in honor of Dr. Corinna Gries.