Xanthoparmelia congesta
≡Parmelia congesta Kurok. & Filson, Bull. Natnl Sci. Mus., Tokyo, ser. B, 1: 36 (1975).
Description : Thallus adnate on rock, 7–10 cm diam. Lobes mostly imbricate, ±contiguous, plane not ascending, irregular, irregularly branching, not constricted at branch points, 0.5–3(–7) mm wide. Upper surface yellow to yellow-green, glossy in parts to matt, emaculate, wrinkled-ridge centrally, without isidia or soredia, margins black-rimmed. Lower surface wrinkled to smooth, black, rhizinate. Rhizines sparse, simple, robust, 0.2 mm long, black. Apothecia subpedicellate, 3–9 mm diam., disc concave, red-brown to brown-black; thalline exciple undulate, developing radiating cracks. Ascospores 6–8 × 4–5.5 μm. Pycnidia common. Conidia bifusiform, 5–6 × 0.5 μm.
Chemistry : Cortex K−; medulla K+ yellow→dark-red, C−, Pd+ yellow-orange; containing norstictic (major), connorstictic, salazinic, consalazinic, protocetraric (tr.) and usnic acids.
S: Canterbury (Lake Ohau, Glen Lyon Stn), Otago (Lindis River near Cluden, Coal Creek near Roxburgh). On rocks in dry grassland. Known also from Australia and Tasmania (Elix 1994s: 226; McCarthy 2003c, 2006).
Australasian
Illustrations : Kurokawa & Filson (1975: pl. 1, fig. 1 – as Parmelia congesta); Filson & Rogers (1979: pl. 11B – as P. congesta); Hale (1990: 92, fig. 33A); Kantvilas et al. (2002: 162, 188).
Xanthoparmelia congesta is characterised by: the saxicolous habit; the tightly adnate, mat-forming thallus of imbricate lobes; the black lower surface; and norstictic acid in the medulla.
