Lobothallia cosmopolites
Description : Lichenicolous, on host thallus and rarely on apothecial dics, vegetative hyphae dark-brown, septate, single stranded, ramifying to net-like, slightly constricted at septa, hyphal cells, 6–8(–10) × 4–7 μm, upper surface sculptured, punctiform. Ascomata superficial, scattered, subglobose to ellipsoidal, dark-brown to black, roughened, but without setae, 60–100 × 30–45 μm, opening apically with rounded to irregular ruptures, outer cell layers brownish, internal layers hyaline, filling ascomata. Interascal filaments absent. Asci 4–8 per ascoma, broadly clavate to subglobose, 15–20 × 12–15 μm, Arthonia -type, wall apically thickened, with large apical dome, 8-spored. Ascospores colourless at first becoming brown with age, 1-septate, lower cell slightly narrower, often guttulate, young spores with a prominent perispore forming a halo, perisporal sheath later condensing to form a fine, punctiform surface sculpture, 8–10(–11) × 3–4(–5) μm.
S: Otago (Central Otago). Known also from Europe, Scandinavia. Macaronesia, Africa, Asia, North and South America, the Dominican Republic and Australia (Hafellner & Calatayud 1999; Triebel & Scholz 2001; Calatayud et al. 2002, 2004b; Diederich 2003).
Cosmopolitan
Hosts : Widespread on many species of Xanthoparmelia including: X. dichotoma, X. filarszkyana, X. isidiigera, X. mexicana, X. notata, X. substrigosa and X. tinctina. Although not yet positively identified from New Zealand populations, it should be searched for here in these and other species of Xanthoparmelia.
Illustration : Hafellner & Calatayud (1999: 109, fig. 1).
* Lichenostigma cosmopolites is characterised by: the lichenicolous habit (on species of Xanthoparmelia as host); dark-brown to roughened apothecia, without setae and opening apically by rounded to irregular ruptures; ascospores colourless at first becoming brown, 1-septate, halonate, 8–11 × 3–5 μm.
