Caloplaca ferruginea
≡Lichen ferrugineus Huds., Fl. angl.: 444 (1762).
Description : Thallus uneven-cracked, scurfy, whitish or grey-white often thin and evanescent, in irregular patches, 5–10(–15) mm diam. Apothecia common, prominent, sessile, plane to convex, clustered in small groups, 0.1–0.8(1.0) mm diam., disc matt, rusty red-brown to orange-brown; thalline margin not apparent; proper margin thin, entire, persistent, paler than disc. Epithecium densely granular, yellow-brown, 8–16 μm thick. Hymenium 65–80 μm tall, without oil droplets. Paraphyses slender, densely conglutinate, 1.5–2 μm thick, apices not swollen. Asci cylindrical, 50–60 × 13– 15 μm, 8-spored. Ascospores oval-ellipsoidal, 13.5–15 × 6.5– 8.5 μm; septum 5–7 μm thick, ½ length of spore.
Chemistry : Apothecia K+ violet-red; containing emodin, parietin, xanthorin, fallacinal, chloremodin and fragilin.
N: Sine loco (Colenso 6301 – BM). S: Canterbury (The Wolds), Otago (Oturehua, Patearoa, Teviot Valley). On bark and twigs of Cytisus scoparius, Discaria toumatou, Leptospermum scoparium, Salix. Associating with the following lichens: Arthonia radiata, Candelariella vitellina, Physcia adscendens, Ramalina celastri, R. glaucescens, Rinodina exigua, Usnea, Xanthomendoza novozelandica and Xanthoria parietina. Widespread in the Northern Hemisphere (Magnusson 1944b; Thomson 1979; Laundon 1992; Nimis 1993; Santesson 1993; Poelt & Hinteregger 1993; Esslinger & Egan 1995; Wirth 1995b; Egea 1996, John 1996; Kondratyuk 1996b, 1998; Seaward 1996; Boqueras 2000; Diederich & Sérusiaux 2000; Scholz 2000; Coppins & Fletcher 2001f; Hafellner & Türk 2001; Llimona & Hladun 2001; Nimis & Martellos 2003; Santesson et al. 2004). Known in the Southern Hemisphere from South Africa, Hawai'i, New Caledonia, Chile, Argentina, and Australia (Kärnefelt 1988a, 1988b; Elix & McCarthy 1998; Galloway & Quilhot 1999; Calvelo & Liberatore 2001; McCarthy 2003c, 2006).
Cosmopolitan
Illustrations : Wade (1965: 3, fig. 7); Phillips (1987: 170); Foucard (1990: pl. 71); Boqueras (2000: 134, fig. 16F; 135, fig. 17G).
Caloplaca ferruginea is characterised by: the corticolous habit; the thin, scurfy whitish thallus; prominent, crowded, small, rust-red apothecia; oval-ellipsoidal ascospores with a thick septum to ½ the length of the spore. Apothecial discs are sometimes parasitised by * Lichenodiplis lecanorae (q.v.).
