Flora of New Zealand Series

≡Psora saxicola Hoffm., Descr. Adumbr. Pl. Crypt. Lich. 1, 3: 82 (1794).

Description : Flora (1985: 69).

Chemistry : Thallus and apothecia K+ violet red, C−; containing emodin, parietin, xanthorin, and fallacinal (Santesson 1970: 2155 – as Caloplaca murorum).

S: Nelson (Takaka Hill, Mt Owen Ra.), Canterbury (Weka Pass, Castle Hill, Mt Somers, Coal Creek Rangitata Valley, near Temuka), Otago (Maraewhenua, Duntroon, Ngapara, Maheno, Millers Flat), Southland (Clifden). On limestone rocks, and marble, often very common, imparting a characteristic orange-yellow colour to the rocks. On vertical sides of concrete telephone poles and fence posts where it forms small, compact widely scattered cushions amongst Acarospora sp., Lecanora dispersa and Xanthoria elegans. Occasionally also on sloping concrete window ledges (e.g. Millers Flat School), where it occurs together with Candelariella aurella. Records of Fulgensia fulgens in Galloway (1985a: 170) are all referable to C. saxicola. C. saxicola is a bipolar lichen, commonly occurring on nutrient-enriched or calcareous rocks in the Northern Hemisphere where it is known from Great Britain, Europe, Scandinavia, the Arctic, Morocco, Tunisia, Israel, Turkey, India, Asia, North America and Australia (Nordin 1972; Thomson 1979; Hansen et al. 1987a; Søchting 1989; Awasthi 1991; Laundon 1992; Nimis 1993; Poelt & Hinteregger 1993; Santesson 1993; Esslinger & Egan 1995; Søchting & Olech 1995; Egea 1996; Elvebakk & Hertel 1966; John 1996; Galun & Mukhtar 1996; Kondratyuk et al. 1996a, 1996b, 1998; Seaward 1996; Diederich & Sérusiaux 2000; Scholz 2000; Fletcher 2001b; Hafellner & Türk 2001; Llimona & Hladun 2001; Nimis & Martellos 2003; Santesson et al. 2004). In the Southern Hemisphere it is known from Chile, Argentina, Australia, South Shetland Is, the Antarctic Peninsula and continental Antarctica (Galloway & Quilhot 1999; Convey et al. 2000; Calvelo & Liberatore 2001; Øvstedal & Lewis Smith 2001; McCarthy 2003c, 2006).

Bipolar

Illustrations : Moberg & Holmåsen (1982: 187); Wirth (1987: 101; 1995b: 237); Søchting (1989: 254, fig. 22); Dobson (2000: 97; 2005: 107); Øvstedal & Lewis Smith (2001: pl. 1, pl. 21).

Caloplaca saxicola is characterised by: the saxicolous (basicolous rocks) habit; the neat rosettes with radiating, short marginal lobes that are yellow to pale-yellow and densely white-pruinose.It is distinguished from Xanthoria elegans (the two taxa are sometimes sympatric, e.g. on concrete telephone poles and fenceposts) by the distinctly narrower, pruinose lobes that are pale-orange or orange-white and never deep orange-red or white-corticate below.