Parmelina quercina
≡Lichen quercinus Willd., Fl. Berol. Prodr.: 353 (1787).
Description : Thallus closely attached, 5–120 cm diam. Lobes scarcely imbricate, elongate, irregularly branched, 1–2.5 mm wide; cilia sparse to moderately numerous, 0.1–0.15 mm long, black. Upper surface pale greenish grey to whitish grey, convex, dull, distinctly white-maculate on marginal lobes (×10 lens); slightly wrinkled, without isidia or soredia. Lower surface black, rhizinate. Rhizines sparse, simple or rarely squarrosely branched, black. Apothecia common, 2–6 mm wide; disc plane to subconcave; exciple smooth. Ascospores broadly ellipsoidal, 9–12 × 6–9 μm. Pycnidia common. Conidia bacillar, 6–8 × 1 μm.
Chemistry : Cortex K+ yellow; medulla K−, C+ red, KC+ red, Pd−; containing atranorin, chloroatranorin and lecanoric acid (major).
S: Otago (Akatore saltmarsh). On twigs of shrubs, growing with Melanelia, Menegazzia and Teloschistes chrysophthalmus. Widely distributed in temperate regions (McCarthy 2003c, 2006; Nimis & Martellos 2003).
Cosmopolitan
Illustrations : Hale (1976b: 41, fig. 18D, E); Dobson (2000: 271; 2005: 306); Brodo et al. (2001: 486, pl. 566).
Parmelina quercina is characterised by: the corticolous habit; the absence of isidia and soredia; the presence of distinct white maculae on the upper surface of the lobes; and the presence of lecanoric acid in the medulla.
