Buellia demutans
≡Lecidea demutans Stirt., Trans. Proc. Roy. Soc. Victoria 17: 71 (1881).
≡Hafellia demutans (Stirt.) Pusswald in B. Marbach, Biblthca Lichenol. 74: 259 (2000).
Description : Thallus white to pale-grey, continuous to areolate. Prothallus evanescent or visible as a delimiting thin, black line. Apothecia scattered to contiguous, adnate to sessile, rounded to 1 mm diam.; disc black, plane to subconvex, epruinose. Hymenium colourless, inspersed with oil droplets, 110–130 μm tall; epithecium dark-brown. Hypothecium dark-brown, to 100 μm thick, asci 8-spored. Ascospores Callispora -type, (22–)25–30(–40) × 10–12(–14) μm, ornamentation warted to ridged.
Chemistry : Thallus K+ yellow; containing atranorin and diploicin.
S: Canterbury (Banks Peninsula, Summit Road S of Okains Bay). On roadside rocks. Known also from Brazil, Uruguay, Paraguay, South Africa, Hawai'i, New Caledonia and Australia (Mayrhofer 1984b; Sheard 1992; Pusswald 1995; Marbach 2000; McCarthy 2003c, 2006).
Pantropical
Illustration : Marbach (2000: 262, fig. 124 – as Hafellia demutans).
Buellia demutans is characterised by: the saxicolous habit; the grey-white thallus; adnate to sessile, black apothecia; ascospores with subapical thickenings (Callispora -type), 8 per ascus, (22–)25–30(–40) × 10–12(–14) μm, ornamentation warted to ridged.
