Carbonea assentiens
≡Lecidea assentiens Nyl. in J. Crombie, J. Bot. 13: 334 (1875).
Description : Thallus whitish to pale yellowish or greyish white, to 0.3 mm thick, rimulose, effuse, to 4 cm diam., with a well-developed black, marginal prothallus. Medulla I+ blue. Apothecia black, often angular, to 0.6 mm diam., sessile, often crowded, margins thin, protruding, concolorous with disc. Exciple black to 50–60 μm wide. Hypothecium colourless, 80–90 μm thick, of densely compacted hyphae. Hymenium hyaline, 70–80 μm tall, the upper parts brown-black. Paraphyses slender, 1–2 μm, simple, conglutinate, apical cells swollen, brown-black, 5–7 μm diam. Asci 40–5- × 10–15 μm. Ascospores 10–16 × 5–7.5 μm.
Chemistry : atranorin and zeorin (Hertel 1989).
A: From coastal rocks at high-water mark. Known also from Prince Edward I., Marion I., Kerguelen, South Georgia, the Antarctic Peninsula, Heard I., Bouvetøya, South Orkney Is, South Shetland Is (Hertel 1984a, 1984b, 1987b, 1989; Øvstedal & Gremmen 2001; Øvstedal & Lewis Smith 2001; Søchting et al. 2004).
Austral
Exsiccati : Hertel (1984a: 1).
Carbonea assentiens is characterised by: the saxicolous habit (coastal rocks); the colourless hypothecium; brown-black epithecium; ascospores 10–16 × 5–7.5 μm; and atranorin and zeorin as secondary compounds. Hertel (1989: 213) raised doubts about the placing of C. assentiens in Carbonea, but hesitated to include it either in Lecanora or Adelolecia. Until its taxonomic position is settled it is here treated in Carbonea.
