Physconia adiastola
≡Physcia adiastola Essl., Mycotaxon 5 (1): 299 (1977).
Description : Thallus orbicular to irregular, sometimes pulvinate, 2–6(–10) cm diam. Lobes irregularly to dichotomously branched, ±linear, (0.3–)0.5–1.5(–3) mm wide, plane to concave, especially at commonly upturned tips; both upper and lower cortices paraplectenchymatous and leptodermatous. Upper surface greenish grey to dark-grey or brownish (darker on moistening with water), smooth, sorediate. Soralia irregular to occasionally weakly capitate, largely terminal and marginal (also laminal); soredia coarsely granular to isidioid and often becoming loosely aggregated into piles, (40–)60–90(–120) μm diam., concolorous with thallus to slightly paler or distinctly darker. Lower surface black, often paler at lobe apices, rhizinate. Rhizines numerous, long (to 2 mm) black (sometimes white-tipped), commonly visible from above lobe margins and/or the upturned lobe ends. Apothecia occasional, subpedicellate, to 3 mm diam., with rhizines around the base. Ascospores Physcia -type, (15.5–)17–22.5(–25) × 6–9 μm.
Chemistry : TLC−, all reactions negative.
S: Nelson (NW of Collingwood, Nelson City). On trees in a park (Nelson) and on coastal limestone rocks (Collingwood). Known also from North America and East and South Africa (Esslinger 1977a, 1978b, 2004a; Moberg 1983b, 2004b; Goward et al. 1994b; Swinscow & Krog 1988).
?Cosmopolitan
Illustrations : Esslinger (1977a: 300, fig. 1, 303, fig. 5); Goward et al. (1994b: 107, fig. 9B); Brodo et al. (2001: 539, pl. 645).
Phaeophyscia adiastola is distinguished from P. orbicularis by its usually more linear lobes and its coarsely granular to isidioid soredia that are located in irregularly delimited, marginal or terminal soralia. P. orbicularis has more finely granular soralia located in round to irregular, laminal and submarginal soralia, and this species generally also has somewhat shorter and more rounded lobes (Esslinger 1977a: 300).
