Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.
Life habit: lichenized Thallus: umbilicate-rosette shaped, squamulose, subfruticose, fruticose, gelatinous when wet surface: black, rarely grayish pruinose, smooth, uneven, sometimes tessellate anatomy: ecorticate, homoiomerous, composed of a loose hyphal network surrounding large photobiont cells photobionts: primary one a chroococcoid cyanobacterium, secondary photobiont absent Ascomata: apothecial, laminal on thallus or terminal, orbicular, immersed to semi-immersed; margin: thalloid, indistinct to distinct ontogeny: hemiangiocarpous, ascogonia arising in a tangle of generative hyphae beneath the thallus surface ascoma anatomy: exciple: absent; epithecium: hyaline or brownish yellow; hypothecium: hyaline asci: prototunicate, wall thin, nonamyloid, 8-spored ascospores: simple, ellipsoid, broadly ellipsoid to globose; 9.5-21.5 x 6-14 µm; walls: thick with age, hyaline Conidiomata: pycnidial, laminal, immersed conidia: ellipsoid or bacilliform, c. 3-5 x 1 µm Secondary metabolites: none detected Geography: world-wide in arid, semi-arid to semi-humid regions, rarely in warm temperate regions Substrate: mainly limestone, but also siliceous rock. Notes: Species of Phylliscum, Phyllisciella and Anema are similar in anatomy and external appearance, but their ascomata arise beneath pycnidia and they have a thin exciple. In Phyllisciella the conidia are filiform. Species of the Phylliscum demangeonii group lack paraphyses and have tapered ascus tips. In Anema the apothecia have a prominent thalline margin.