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: thin, smooth and continuous to ± rimose surface: white, gray, to pale or deep brown, often with an olive or greenish tinge Ascomata: (0.3-)0.5-2(-3) x 0.1-0.2(-0.25) mm, sub-immersed to sessile, scattered to clustered, simple or often furcate, sometimes stellate or forming interlinking network; disc: slit-like, slightly widening when old exciple: closed below, K- hymenium: (45-)50-60(-65) µm, I+ reddish; subhymenium 15-30 µm; epihymenium: brownish; paraphysoids: to 1 µm wide asci: cylindric-clavate, 43-55 x 11-12 µm (Vulgata-type) ascospores: narrowly fusiform, ± tapered at one end, straight or slightly curved, hyaline, 4-7(-8)-septate, (15-)19-30(-40) x (2.5-)3-4(-4.5) µm (Vulgata-type) Pycnidia: often numerous, immersed, intermixed with the lirellae conidia: curved, 9-18 x 1 µm Spot tests: thallus K-, C-, KC-, P- Secondary metabolites: none detected. Substrate and ecology: on ±shaded, smooth, young bark or smooth areas on old trunks on a wide range of tree species, in humid situations; on Cupressus macrocarpa, Lycium californicum, Quercus agrifolia World distribution: widespread in Northern Hemisphere, also mentioned from Australia Sonoran distribution: southern California. Note: Opegrapha vulgata differs from O. niveoatra mainly by its longer conidia.