Flora of New Zealand Series

≡Parmelia gardneri C.W.Dodge, Ann. Missouri Bot. Gard. 46: 179 (1959).

Description : Thallus coriaceous, loosely to closely attached, 4–8(–12) cm diam. Lobes imbricate or not, 5–12 (–15) mm wide, subirregular to sublinear, rounded, margins subascendent becoming subrevolute centrally, ±sinuous, crenulate to incised often becoming sublaciniate, without cilia or sparsely ciliate, cilia 0.2–0.5 mm long. Upper surface pale-grey to grey-green, emaculate, wrinkled or cracked centrally, sorediate, without isidia. Soralia marginal, linear on revolute lobes, becoming subcapitate; soredia granular, grey-white. Lower surface wrinkled, black, with a wide, brown or mottled marginal naked zone, rhizinate centrally. Rhizines simple, short, almost papillate, 0.1–0.2 mm long, black, sparse. Apothecia rare, sessile to subpedicellate, laminal, 2–8(–10) mm diam., disc imperforate, brown, thalline exciple thick, eciliate, sorediate. Ascospores 24–26 × 12–14 μm. Pycnidia not seen.

Chemistry : Cortex K+ yellow; medulla K−, C−, KC+ red-brown, Pd+ deep orange; containing atranorin, chloroatranorin, protocetraric acid (major), an unidentified fatty acid and ±butlerin D (tr.).

N: South Auckland (Te Aroha). On rocks in pasture. Still very poorly collected and understood in New Zealand. Known also from Australia, Africa, Thailand, Papua New Guinea, Mexico, North and South America and Gough I. (Swinscow & Krog 1988; Elix 1994p; Louwhoff & Elix1999; Becker 2002; Elix & Gremmen 2002; Louwhoff & Elix 2002b; Nash & Elix 2002g; Wolseley et al. 2002; McCarthy 2003c, 2006).

Pantropical

Illustrations : Krog & Swinscow (1981: 183, fig. 10 – as Parmelia gardneri); Swinscow & Krog (1988: 177, fig. 88); Louwhoff & Elix (1999: 58, fig. 21).

Parmotrema gardneri is characterised by: the saxicolous habit; the loosely adnate to adnate, coriaceous thallus; the presence of marginal soralia sometimes spreading submarginally; eciliate to sparsely ciliate lobe margins; and protocetraric acid in the medulla. It is the sorediate counterpart of P. zollingeri.