Lecanora plumosa
Description : Thallus thin, plane, continuous to verrucose, yellow-brown to orange-grey or greenish yellow, sometimes glossy, epruinose; soredia absent. Prothallus whitish to greyish present at margins or absent. Apothecia immersed at first, becoming sessile, 0.4–0.7 mm diam, disc wax-coloured or pale- to greenish orange, not or only very slightly pruinose; margins concolorous with thallus, thin, entire to verrucose. Amphithecium with large crystals (pulicaris -type). Parathecium hyaline, 10–15 μm thick, with numerous small crystals, dissolving in K. Epithecium yellow-brown to pale-brown dissolving in K, 10–15 μm thick, with numerous crystals (chlarotera -type). Hymenium and hypothecium hyaline. Paraphyses sparingly branched, not thickened at apices. Ascospores ellipsoidal, 8–11.5 × 4–6.5 μm.
Chemistry : Thallus and apothecial margins K+ yellow, C−, Pd+ pale-orange; containing atranorin (major), 2'- O -methylperlatolic acid (major), chloroatranorin (minor), 2'- O -methylisohyperlatolic acid (minor) and 2'- O -methylsuperlatolic acid (minor).
N: Northland. On coastal rocks in shade. Known also from North and South America, South Africa, Lord Howe I. and Australia (Lumbsch 1994; Guderley 1999; Lumbsch & Elix 2004).
Palaeotropical
Illustrations : Lumbsch (1994: 122, fig. 65E, F; 126, fig. 66A, B); Guderley (1999: 218, fig. 21C).
Lecanora plumosa is characterised by: the saxicolous habit; the pale apothecial discs; and the 2'- O -methylperlatolic acid chemosyndrome. It is close to L. helva, which is restricted to corticolous substrata, and has a thicker thallus and broader ascospores. L. cenisioides is somewhat similar, but has apothecia that are constricted at the base, and smaller ascospores.
