Xanthoparmelia philippsiana
≡Parmelia philippsiana Filson, Muelleria 4: 324 (1981).
Description : Thallus small-foliose, adnate to tightly adnate on rock, to 6 cm diam. Lobes contiguous throughout, sublinear, irregularly branched, 0.5–1.5 mm wide, apices rounded. Upper surface pale yellowish green, weakly convex, slightly glossy, sparsely maculate (×10 lens), smooth, isidiate, without soredia, margins brown-black. Isidia dense, cylindrical, coralloid, small and simple at margins, becoming taller (to 2 mm tall) and branched centrally, forming a diffract crust, apices syncorticate and intact. Lower surface black or dark-brown in parts, rhizinate. Rhizines from margins to centre, sparse, simple, black. Apothecia rare, sessile to subpedicellate, to 8 mm diam., disc plane to undulate, red-brown to brown-black; thalline exciple thin, crenate, isidiate. Ascospores 7–9 × 5–6 μm. Pycnidia not seen.
Chemistry : Cortex K−; medulla K+ yellow, C−, KC−, Pd+ brick-red; containing usnic, stictic, constictic, norstictic (tr.) and cryptostictic (tr.) acids.
S: Nelson (Denniston Plateau). On sandstone rocks. Known also from Tasmania and Macquarie I. (Elix 1994s: 278; McCarthy 2003c, 2006).
Australasian
Illustrations : Hale (1990: 174, fig. 59A); Elix (1994s: 277, fig. 102A).
Xanthoparmelia philippsiana is characterised by: the saxicolous habit; the rosette-forming, small-foliose thallus; tall, dense, coralloid isidia; and metabolites of the stictic acid complex in the medulla.
