Xanthoparmelia barbellata
≡Parmelia barbellata Kurok., Bull. Natnl Sci. Mus., Tokyo, ser. B, 8: 35 (1982).
Description : Thallus loosely adnate to adnate or subpulvinate on rocks or spreading over soil and pebbles, 4–6 cm diam. Lobes imbricate or not, plane, irregularly branched, becoming laciniate, 1–3 mm wide, without lobules, laciniae 0.5–1.5 mm wide, apices subrotund. Upper surface yellow-green, darkening in older parts, glossy or matt, emaculate, smooth, without isidia or soredia, lobe margins blackened. Medulla white, intermittently yellow or orange (skyrin) adjacent to lower cortex. Lower surface pale-brown or brown-black, rarely orange, rhizinate. Rhizines sparse to moderately dense, subapical, simple or dichotomously branched, 0.5–1.2 mm long, concolorous with lower surface. Apothecia sessile, 2–8 mm diam., disc concave to undulate-distorted, glossy, brown to dark-brown; thalline exciple thin, involute, entire to deeply lacerate. Ascospores 6–7 × 3.5–5.5 μm.
Chemistry : Cortex K−; medulla K+ yellow→dark-red, C−, KC+ red, Pd+ intense orange; containing norstictic, connorstictic, salazinic, consalazinic and usnic acids and skyrin (in pigmented medulla).
S: Otago (Observation Pt, Alexandra). On rocks on flat ground. Known also from SE Australia (Elix 1994s; McCarthy 2003c, 2006).
Australasian
Illustration : Kurokawa (1982: 41, fig. 1).
Xanthoparmelia barbellata is characterised by: the saxicolous habit; the brown lower surface; simple and dichotomously branched rhizines; yellow or orange medulla adjacent to lower cortex (presence of skyrin); and norstictic and salazinic acids in the medulla. It is similar to X. substrigosa, but this species has a more densely rhizinate lower surface, and lacks a pigmented medulla.
