Nash, T.H., Ryan, B.D., Gries, C., Bungartz, F., (eds.) 2002. Lichen Flora of the Greater Sonoran Desert Region. Vol 1.

Thallus: foliose, rosette-shaped, lobate lobes: stellately radiating, becoming striate upper surface: dark olive green, composed of only one or two discontinuous layers of cells (not a real cortex); with or without isidia or lacinae, soredia absent photobiont: primary one a filiform cyanobacterium (Scytonema), commonly with intercalary heterocysts, secondary photobiont absent lower surface: pale olive, pseudoparenchymatous with short celled longitudinally extended hyphae Ascomata: apothecial, usually deep red-brown, sessile, with a thalline margin or proper margin formed by a pseudoexciple; hymenium: generally 50-100 micrometer, I+ deep blue; paraphyses: simple or sparsely branched, end cells thickened ontogeny: hemiangiocarpic asci: cylindrical or clavate, with apically thickened wall, 8-spored ascospores: simple or once septate at maturity, colorless, ellipsoid, fusiform or acicular Conidiomata: pycnidial, laminal, ostiole brown conidia: rod-shaped, produced laterally and/or terminally Secondary metabolites: none detected Geography: southern and SW Europe, northern Africa as well as SW North America Substrate: on moist siliceous rocks or on the bark of trees in somewhat closed woodland. Notes: The distinctive olive-green color separates Koerberia from small Collema or Leptogium species.