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: fruticose-filamentous to subfruticose or caespitose, prostrate, closely appressed (under 1 cm tall), sometimes becoming compacted and subcrustose centrally, loosely or ± tightly attached to the substrate by scattered, expanded, disc-like holdfasts (hapters) at unspecialized attachment points along the length of the branches and not merely at the base, base sometimes dying such that the thalli often form rosettes branching: ± thickly isotomic-dichotomous (often strictly so, but sometimes anisotomic) branches: up to 4-10 (-15) mm long, mostly narrow, up to 0.1-0.5 mm wide (to 1-2 mm wide near base), pliant or brittle, solid, in section rounded to flattened (dorsiventrally compressed) parallel to the substrate surface: brown to deep black-brown, dull to slightly shiny, usually concolorous except where attached to substrate, even or uneven; lacking pseudocyphellae, true lateral spinules, and vegetative propagules cortex: 2-layered; outer layer: almost paraplectenchymatous, with cells rectangular to irregular and knobby at the surface, inner layer: prosoplectenchymatous, composed of periclinal, longitudinal hyphae, 75-85 µm thick medulla: white, hyphae not granular encrusted nor ornamented; cell walls: with Cetraria-type and intermediate-type lichenan, and possibly traces of isolichenan photobiont: primary one a chlorococcoid alga, secondary photobiont absent Ascomata: apothecial, sometimes frequent, lateral, roundish, sessile; thalloid margin: concolorous with thallus, slightly prominent to prominent, persistent to pressed back, not incurved, sometimes "ciliate" (with elongated, spine-like projections); disc: dark brown to almost black; exciple: ± distinct, slightly gelatinized, hyaline; hymenium: hyaline below, olive-brown above, turning grayish greenish yellow in K, 75-85 µm tall; paraphyses: branched and anastomosing, the tips not capitate or pigmented asci: clavate, 20-45 x 6.7-9.0 µm, thick-walled, Lecanora-type, I+ blue, with robust tholus, 8-spored ascospores: simple, ellipsoid or broadly ellipsoid, hyaline at maturity, smooth, without perispore or a distinct endospore thickening, I-, c. 7-12 x 6-8 µm Conidiomata: pycnidial, very common, laminal, immersed, with wide ostioles conidia: bifusiform, simple, colorless Secondary metabolites: none detected Geography: circumbipolar and alpine in temperate regions Substrate: on acidic rock, rarely on old wood or baked soil. Notes: It is distinguished from rock or soil species of Bryoria by its 2-layered cortex, that has rectangular to irregular and knobby cells at the surface, its low, prostrate habit and its attachment by hapters, lack of isidia, soredia and pseudocyphellae, its frequent pycnidia, and its absence of secondary lichen products (see also Common and Brodo 1995).