Pseudocyphellaria aurata (Ach.) Vain.
Sticta aurata Sm. in Ach., Meth. Lich.: 277 (1803).
Thallus orbicular to irregularly spreading, loosely to closely attached, 5-10(-15) cm diam., corticolous. Lobes 3-12 mm wide and to 30 mm long, branching irregular, lobes often discrete from margins to centre, broadly rounded or indented, ± discrete at margins ± imbricate centrally, margins slightly thickened below, entire, sinuous, with pseudocyphellae, or with erose to ± linear wavy soralia. Upper surface bright lettuce-green when wet, pale olive-brown or buff when dry becoming reddish on storage, smooth, coriaceous, ± scabrid-areolate towards margins, undulate to shallowly pitted or wrinkled, occasionally cracked and then with small, granular regenerating lobules along margins of cracks. Soredia yellow, coarsely granular in mainly marginal, linear, elongate, sinuous soralia, eroding lower margin of lobes, often ± revolute, convolute or subascending, rarely spreading over upper surface. Medulla yellow. Photobiont green. Lower surface pale buff or yellowish-pink, wrinkled-uneven, tomentose to margins, tomentum thin, silky, pinkish-buff or whitish at margins, thicker and darker to ± chocolate-brown centrally. Pseudocyphellae yellow, numerous, ± rounded 0.05-0.3 mm diam., ± elevated, decorticate area plane, level with or slightly sunk in tomentum. Apothecia not seen. Chemistry: Pulvinic acid, pulvinic dilactone, calycin, unidentified (?)neutral compounds possibly triterpenes and/or sterols (Dr A.L. Wilkins pers. comm.).
N: North Auckland (Three Kings Is) to Wellington. Most frequent in northern coastal forest north of Auckland.
Cosmopolitan
P. aurata is characterised by the yellow soredia in sinuous, marginal soralia, the yellow medulla and yellow pseudocyphellae. It is distinguished from P. poculifera by the entire margins which never develop phyllidia, and from P. rubella by the glabrous upper surface and the nature of the soralia.
