Xanthoparmelia tegeta
Description : Thallus loosely to moderately adnate to rock, 4–7 cm diam. Lobes contiguous to imbricate, plane, linear-elongate, dichotomously to subirregularly branched, irregularly constricted at branch points, 0.3–1(–1.5) mm wide, laciniae often densely imbricate, forming a compact mat. Upper surface yellow-green, darkening with age, glossy to matt, emaculate, smooth, without isidia or soredia, margins of lobes conspicuously blackened. Lower surface glossy, black, rhizinate. Rhizines moderately dense, ±projecting beyond margins, often rhizinate to margins and appearing ciliate, simple or occasionally dichotomously branched, to 2 mm long, black. Apothecia rare, sessile, 0.5–1.5 m diam., disc concave, dark-brown; thalline exciple smooth. Ascospores 6–9.5 × 3.5–5.5 μm. Pycnidia common, Conidia bacillar, 6–7 × 0.5 μm.
Chemistry : Cortex K−; medulla K+ yellow, C−, KC−, Pd+ orange; containing stictic (major), constictic, cryptostictic, norstictic and usnic acids.
S: Nelson (Parachute Rocks St Arnaud Ra.), Otago (Lindis River near Cluden, Butcher's Dam Alexandra). On subalpine rocks. Known also from Australia and South Africa (Elix 1994s: 296; McCarthy 2003c, 2006).
Southern Xeric
Illustrations : Elix et al. (1986b: 339, fig. 36); Elix (1994s: 297, fig. 105A); Kantvilas et al. (2002: 165)
Xanthoparmelia tegeta is characterised by: the saxicolous habit; a compact, densely imbricate mat of laciniae; constricted linear-elongate lobes; a black lower surface with long, slender rhizines; and the stictic acid complex in the medulla.
