Lichenostigma Haffelner,
Type : * Lichenostigma maureri Hafellner
Description : Lichenicolous, developing on upper surface of host. Ascomata apothecia, immersed to sessile on host tissue, rounded, cushion-forming, rather soft, black or dark-brown, outer wall cells brown, inner cells colourless. Paraphysoids absent, asci instead developing throughout a mass of paraplectenchymatous tissue. Asci, fissitunicate, broadly saccate, at first with a well-developed thick apical dome, becoming much reduced in ripe asci, 8-spored. Ascospores 1-septate or rarely submuriform, at first halonate and colourless, at maturity brown and sculptured.
Lichenostigma, included in the family Lichenotheliaceae (Lawrey & Diederich 2003; Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005) is a genus of c. 16 species (Calatayud et al. 2002, 2004b). It is characterised by the following characters: minute, arthonioid ascomata, 70–120 μm in diam.; centrum I+ or I−, subglobose to broadly ovate, fissitunicate asci develop in a paraplectenchymatous tissue, and no interascal filaments are formed; asci are broadly saccate and contain 8, hyaline or brown, 1-septate to submuriform ascospores, 9–12 × 4.5–6 μm. It is known from thalli of Aspicilia, Buellia, Diploschistes, Diplotomma, Lobothallia, Pseudevernia, Squamarina, Usnea and Xanthoparmelia (Hafellner 1982; Thor 1985; Diederich 1986; Hawksworth 1986b; Navarro-Rosinés & Hafellner 1996; Hafellner & Calatayud 1999; Llimona & Hladun 2001; Calatayud et al. 2002, 2004b; Etayo 2002; Calatayud & Barreno 2003; Diederich 2003; Ihlen 2004b). One species is probably widespread in New Zealand and should be searched for here.
