Xanthoparmelia arapilensis
≡Parmelia arapilensis Elix & P.M.Armstr., Austral. J. Bot. 31: 467 (1983).
Description : Thallus loosely adnate on rocks or soil, yellow-green, irregularly lobate, 6–8 cm diam. Lobes irregular, sparingly imbricate or not, 2–5(–8) mm wide, the apices crenulate, ±rounded. Upper surface slightly glossy to matt, maculate or not, without isidia or soredia, becoming wrinkled-cracked with age, the margins commonly blackened. Lower surface pale-ivory to tan, darker towards apices, densely to moderately rhizinate. Rhizines concolorous with lower surface, simple or sparingly branched. Apothecia adnate, 2–5 mm diam., disc dark-brown; thalline exciple thick and involute at first, later becoming undulate-cracked. Ascospores 9–10 × 5–6 μm. Pycnidia common. Conidia bacillar to subbifusiform, 5–6 × 0.5 μm.
Chemistry : Thallus K−; medulla K+ yellow→red, C−, Pd+ intense yellow; containing norstictic (major), connorstictic, salazinic (tr.), consalazinic (tr.), protocetraric (tr.) and usnic acids.
S: Marlborough (Molesworth, Kaikoura coast), Canterbury (Motukarara, Rangitata Gorge), Otago (Cluden near Lindis Pass, Macraes Hill, Nuggets). On rocks, coastal and inland. Known also from Australia including Tasmania (Elix 1994s; McCarthy 2003c, 2006).
Australasian
Illustrations : Elix & Armstrong (1983: 468, fig. 1); Elix (1994s: 195, fig. 69)
Xanthoparmelia arapilensis is characterised by: the saxicolous/terricolous habit; the broad lobes; the pale lower surface with moderately dense, simple or sparingly branched rhizines; and norstictic acid in the medulla.
