Carbonea (Hertel) Hertel
Type : Carbonea atronivea (Arnold) Hertel [=Lecidea atronivea Arnold]
Description : Thallus crustose, ±superficial, sometimes immersed and not apparent, or commensalistic without an independent thallus. Photobiont green, chlorococcoid. Ascomata apothecia, black, shining, subconcave to plane or subconvex; disc epruinose. Thalline exciple absent. Proper exciple well-developed, persistent, raised, black; hyphae dark-pigmented. Epithecium blue-green to emerald-green. Hymenium colourless in lower parts, dull blue, or ±vivid blue-green to bright emerald-green above, I+ blue. Hypothecium pale yellow-brown to blue-green in upper parts, dark red-brown to brown-black below, K−. Hamathecium of conglutinated simple or branched paraphyses, 1–2 μm thick, the apical cell to 3.5–7 μm wide, coherent in a gelatinous matrix. Asci 8-spored, Lecanora -type (Malcolm & Galloway 1997: 186), clavate. Ascospores oblong-ellipsoidal, simple, small, colourless; perispore absent, sometimes with a plasma bridge and appearing spuriously 1-septate. Conidiomata pycnidia, immersed. Conidiogenous cells elongate, ampulliform, enteroblastic, arising singly or in small groups. Conidia curved, thread-like, simple, colourless.
Key
Carbonea is a genus of c. 20 species, two of which are lichenicolous (Triebel 1989: 126–129; Alstrup & Hawksworth 1990; Knoph et al. 2004) included in the family Lecanoraceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005). It is distinguished by the vivid blue-green hymenium; the opaque, "carbonised", black, proper exciple; asci Lecanora -type without any amyloid zone between the masse axiale and the rather thin outer ascus wall; by branched paraphyses with gelatinous walls (a character separating it from species of Lecidella); and a lack of xanthones (Hertel 1967, 1984b; Triebel 1989; Rambold 1989; Knoph 1999). Some species are lichenicolous, the majority being found in alpine habitats on siliceous rocks. Four species occur in New Zealand (Hertel 1985b, 1987b, 1989, 2001; Rambold 1989).
