Caloplaca holocarpa
≡Verrucaria obliterata var. holocarpa Hoffm., Dtschl. Fl.: 179 (1796).
=Caloplaca thomsonii Zahlbr., Denkschr. Akad. Wiss. Wien math.-naturwiss. Kl. 104: 368 (1941).
Caloplaca thomsonii. Lectotype: New Zealand. Southland, Clifden on limestone rocks, J.S. Thomson T 2264 [A11] – CHR 374039 [fide Galloway (1985a: 70)].
Description : Thallus inconspicuous, scurfy-granular, whitish, grey-brown to black, often lacking, K−, spreading in irregular patches, 1–5(–8) cm diam. Apothecia common, conspicuous, sessile, scattered to crowded, rounded or contorted through mutual pressure, 0.1–0.8(–1) mm diam., disc shallowly concave at first, becoming plane to distinctly convex, matt, orange to dull orange-red, thalline margin greyish, soon disappearing, proper margin persistent, entire, slightly glossy, paler than disc. Epithecium yellow-brown, granular, (5–)8–16 μm thick. Hymenium colourless, without oil granules, 50–70 μm tall. Paraphyses simple, septate, 2 μm thick, apices swollen, to 5 μm diam. Asci cylindrical to clavate, 50–55 × 12–15(–17) μm, 8-spored. Ascospores ovoid to broadly ellipsoidal, biseriate in ascus, apices rounded, 10–15(–16.5) × 5–8.5 μm, septum 3–5 μm thick, c. ¼ to ⅓ length of spore.
Chemistry : Apothecia K+ violet-red; containing emodin, parietin, xanthorin, fallacinol, erythroglaucin and fallacinal (Santesson 1970: 2154).
N: Northland (Rawene, Waipu Caves), South Auckland (Waikaretu), Wellington, sine loco (Charles Knight – BM). S: Marlborough (Goose Bay, Kaikoura), Canterbury (Weka Pass, Hanmer, Mt Palm, Castle Hill, Cave Stream, Prices Valley, Banks Peninsula, Mt Somers, Milford), Otago (Duntroon, Ngapara, Matanaka, Raggedy Ra., Chapman Road near Alexandra, Cornish Head), Southland (Otautau, Sharks Tooth, Forest Hill, Castle Rock, Clifden). Ch: (Big Bush). On limestone and calcareous sandstone, mortar, and bare, silty dry soil and salt-pan, also on dead or decorticated wood (railings, fenceposts etc.). Nineteenth century accounts of New Zealand lichens (e.g. Nylander 1888: 59; Hellbom 1896: 67) refer this species to Lecanora pyracea or Caloplaca pyracea. Common on concrete often with Candelariella aurella. On limestone it associates with Caloplaca citrina, C. decipiens, C. saxicola, Candelariella vitellina, Diplotomma alboatrum, Lecanora albescens, L. crenulata, L. dispersa, L. pseudistera, Leptogium plicatile, Placynthium nigrum etc. Widespread in the Northern Hemisphere where it is known from Great Britain, Europe, North Africa, Israel, Turkey, Ukraine E to Iran and Saudi Arabia, Thailand, South Africa and North America (Thomson 1979; Laundon 1992; Nimis 1993; Santesson 1993; Esslinger & Egan 1995; Egea 1996; Galun & Mukhtar 1996; John 1996; Kondratyuk et al. 1996a, 1996b, 1998; Seaward 1996; Boqueras 2000; Diederich & Sérusiaux 2000; Scholz 2000; Fletcher & Coppins 2001i; Hafellner & Türk 2001; Llimona & Hladun 2001; Wolseley et al. 2002; Nimis & Martellos 2003; Santesson et al. 2004). In the Southern Hemisphere it is known from Chile, Argentina, and Australia (Galloway & Quilhot 1999; Calvelo & Liberatore 2001; McCarthy 2003c, 2006).
Cosmopolitan
Illustrations : Wade (1965: 3, fig. 5); Brodo (1981: 43, fig. 15); Moberg & Holmåsen (1982: 185); Wirth (1987: 99; 1995b: 215); Foucard (1990: 104); Laundon (1992: 145, fig. 7D); Dobson (1992: 79; 2000: 94; 2005: 103); Boqueras (2000: 135, fig. 17J; 151, fig. 18B); Øvstedal & Lewis Smith (2001: pl. 16, pl. 17); Brodo et al. (2001: 202, pl. 167).
According to Søchting & Stordeur (2001: 471), the Caloplaca holocarpa complex is characterised by a ±insignificant, mostly greyish thallus; orange discs with ±concolorous margins; and medium-sized, polarilocular spores with a broad septum, [New Zealand material is 10–13.5(–15) × 5–8 μm, septum 3–5 μm thick]. They recognise that this broad circumscription accommodates a number of taxa whose taxonomy is at present unresolved. Taxa within this circumscription are found on bark, lignum and rock (Wade 1965), although later authors, following Magnusson (1946), provisionally use the name C. pyracea (Ach.) Th.Fr. for lignicolous and corticolous members of the C. holocarpa complex, and C. lithophila H.Magn., for saxicolous specimens (Hansen et al. 1987a; Poelt & Hinteregger 1993; Arup 1994). As discussed by Søchting & Stordeur (2001: 471) the taxonomy of the C. holocarpa – C. pyracea complex is still unresolved, but it appears to comprise several taxa distinguished by substratum requirements and climatic conditions. Molecular evidence demonstrates that corticolous C. pyracea and the saxicolous C. lithophila H.Magn., orm a monophyletic group (Arup & Grube 1999). Apothecia are sometimes parasitised by * Muellerella lichenicola (q.v.).
