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: terete-foliose, decumbent or caespitose lobes: rather broad to narrow, c. 0.5-11.0 mm wide; apices: rounded to fusiform, eciliate upper surface: pale olive brown to greenish black, rather smooth to rough, occasionally ridged or knobby, rather shiny to dull, occasionally pruinose; isida: sometimes present, flattish, with white cortex; soredia and lobules: absent; pseudocyphellae: sparse, indistinct and immersed upper cortex: non-pored epicortex, prosoplectenchymatous medulla: white, loosely packed photobiont: primary one a Trebouxia, secondary photobiont absent lower cortex: present or absent lower surface: pale brown, attached by simple black rhizines; cyphellae, pseudocyphellae and tomentum: absent Apothecia: frequent, marginal to laminal, at first concave, later becoming convex, pedicellate; margin: prominent with thalloid rim; disc: imperforate, dark olivaceous brown; exciple: hyaline; epithecium: brown or brownish yellow; hypothecium: hyaline asci: lecanoral, wall layers apex thickened; apex: amyloid, with wide axial body divergent towards apex; 8-spored ascospores: simple, ellipsoid to broadly ellipsoid, 6-10.5 x 2.5-5 micrometer; walls: thin, hyaline, not amyloid Conidiomata: pycnidial, laminal or marginal, immersed or emergent sessile conidia: bifusiform, 5-7 x 1 micrometer Secondary metabolites: fatty acids; lichesterinic and protolichesterinic acids and 2-3 other low-Rf fatty acids in the medulla Geography: hypermaritime or temperate /boreal areas of western North America and low to intermediate elevations in Spain Substrate: bark or wood. Notes: A lower cortex is only present in K. merrillii. Potentially the second species of Kaernefeltia may be found in the Sonoran region as it is known from farther north in California.