Rhizocarpon viridiatrum
≡*Lichen viridiatrum Wulfen in N.J. von Jacquin, Collnea Bot. 2: 186 (1788).
Description : Flora (1985: 507).
Chemistry : Rhizocarpic acid and norstictic acid (tr.) (Hertel 1985b: 335).
N: Northland (Kawakawa Bay, Papanui Point). S: Canterbury (Banks Peninsula, Devil's Gap, Bankside Scenic Reserve, Mt Sebastopol, Hooker Valley, Lake Pukaki, Lynn Stream Mt Peel), Otago (Silver Peaks, Flagstaff). On lowland and coastal to subalpine rocks in exposed, sunny situations, commonly parasitic on grey species of Aspicilia (Hertel 1985b). Known also from Great Britain, Europe, Scandinavia, Morocco, Turkey, the Ukraine, North America, Chile and Australia (Lynge 1932; Feuerer 1978; Hertel & Leuckert 1979; Purvis et al. 1992; Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Wirth 1995a, 1995b; Egea 1996; John 1996; Kondratyuk et al. 1996a; Galloway & Quilhot 1999; Diederich & Sérusiaux 2000; Scholz 2000; Hafellner & Türk 2001; Llimona & Hladun 2001; Coppins 2002b; McCarthy 2003c, 2006; Nimis & Martellos 2003; Feuerer & Timdal 2004; Santesson et al. 2004).
Cosmopolitan
Illustrations : Runemark (1956a: 18, fig. 4A; 23, fig. 7C; 24, fig. 8E; fig. 19–D; 80, fig. 20 A, B; 81, fig. A, B; 82, fig. 22B); Feuerer (1978: 100); Wirth (1987: 418; 1995b: 819); Foucard (1990: pl. 285); Dobson (1992: 300; 2000: 345; 2005: 391); Malcolm & Malcolm (2000: 90).
* Rhizocarpon viridiatrum is characterised by: the lichenicolous habit (parasitic on species of Aspicilia); the I− medulla; the thick hypothecium, 200–300 μm thick; clavate. 8-spored asci, 80–110 × 25–30 μm; and muriform ascospores with few septa, 12–27 × 7–17 μm; and a secondary chemistry of rhizocarpic and norstictic acids.
