Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2004. Lichen Flora of the Greater Sonoran Desert Region. Vol 2.
Apothecia: aggregated to almost confluent on the thallus and the apothecial margin of the host, at first completely immersed, ±perithecioid, breaking through the cortex of the lichen, becoming apothecioid when mature, but remaining immersed, black margin: not prominent, thin and smooth, concolorous to the disc, 100-120 µm in diam. exciple: basally hyaline to green, laterally grayish to brownish green, K- or more intensively brown, N+ olivaceous-brown, composed of several rows of elongate cells; excipular hairs: absent epihymenium: pale green hymenium: hyaline, 55-60 µm tall paraphyses: simple or branched, hyaline, not or slightly swollen at the apices, 1.5-2 µm thick; subhymenium: 5-10 µm thick asci: subcylindrical, wall apically not thickened, I and KI-, 48-55 x 67 µm, 8-spored ascospores: ellipsoid, straight or slightly curved, simple, hyaline, smooth, with obtuse ends, 8-10.5 x 3-4 µm. Conidiomata: pycnidial, similar to perithecioid apothecia and intermixed with them; wall: the same color as the exciple; conidiogenous cells: phialidic, ampulliform, hyaline, 4-5 x 2.5-3 µm conidia: hyaline, simple, subcylindrical to narrowly ellipsoid, basally thickened and truncate, smooth-walled, 5-8 x 0.5-1 µm. Hosts: thallus and thalline border of Dirina ceratoniae (Mallorca) and Roccellina conformis (California), not visibly damaging the host World distribution: Europe (Mallorca) and the western U.S.A. Sonoran distribution: once collected in southern California on the Channel Islands. Notes: The American specimen differs from the type by its larger apothecia (120-200 µm wide, versus 100-120 µm wide in the type material), a shorter hymenium (45-50 µm versus 55-60 µm in the type) and shorter asci (37-43 x 6-7 µm versus 48-55 x 6-7 µm). All other characters, like pigments, ascospores and shape of apothecia, are very similar in both European and American samples. Both populations live on closely related hosts and in a similar habitats. The American material might represent a distinct species, but more samples are needed to understand the degree of variability of the species. The description above is based exclusively on the type specimen from Europe (Mallorca) on Dirina ceratoniae.