Arthonia vinosa
Description : Thallus immersed or thinly powdery to scurfy-granular, effuse, whitish to pale-fawn, commonly stained orange-yellow, pinkish when moist, often with dull yellowish to orange-yellow blotches, K+ purple. Photobiont green, Trentepohlia. Apothecia 0.2–0.5(–0.6) mm diam., rounded, convex, orange-red-brown to brown-black, usually matt, epruinose, in section 85–140 μm tall, yellow-orange-red throughout or brown-red in upper hypothecium, K+ magenta and K+ purple with pigments dissolving. Epithecium indistinct. Hymenium 3–40 μm tall. Hypothecium 45–100 μm thick. Paraphysoids 0.5–1(–1.5) μm diam, mostly neither swollen nor dark-walled above, Ascospores ovoid-ellipsoidal to soleiform, 1-septate, colourless, old spores brown and warted, 11–15 × 4– 5 μm. Pycnidia frequent, 40–60 μm diam., the wall red-brown, K+ purple. Conidia bacillar or slightly curved, (3.5–)4–6 × 1 μm.
N: Wellington (Tararua Ra.). S: Nelson (Mt Arthur). First collected in New Zealand by Leif Tibell (Polly 1996: 20). Known also from Great Britain, Europe, Scandinavia, Tibet, North America (Purvis et al. 1992; Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Scholz 2000; Nimis & Martellos 2003; Obermayer 2004; Santesson et al. 2004).
?Bipolar
Exsiccati : Vězda (1982a: No. 1842).
Illustrations : Wirth (1987: 49; 1995b: 135); Foucard (1990: fig. 22); Dobson (1992: 54; 2000: 62; 2005: 70).
Arthonia vinosa is characterised by: the corticolous habit; the powdery, scurfy-granular, whitish to pale fawnish thallus, often with dull yellowish to orange-yellow (K+ purple) blotches; orange-brown to brown-black apothecia (K+ purple in section); and oval-ellipsoidal to soleiform, 1-septate ascospores, colourless at first becoming brown and warted with age, 11–15 × 4–5 μm.
