Flora of New Zealand Series

=LEPROPLACA (Nyl.) Hue, 1887  

Type : Caloplaca cerina (Ehrh. ex Hedwig) Th.Fr. [=Lichen cerinus Ehrh. ex Hedwig]

Type : Leproplaca xantholyta (Nyl.) Hue [=Lecanora xantholyta Nyl.]

Description : Flora (1985: 60).

Caloplaca, included in the family Teloschistaceae (Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005) is a widespread, cosmopolitan genus of c. 800–1000 species (Kärnefelt et al. 2002; Khodosovtsev et al. 2002; Kärnefelt & Kondratyuk 2004), with taxa known from marine rocks at sea level to high-alpine rocks in all parts of the world including polar regions. In New Zealand, species occur widely on rock (both siliceous rocks and especially also on limestone or calcareous sandstone), living bark, decorticated wood, silty soil, clay and on high-alpine mosses (where they are parasitic), occupying habitats from sea level to 3000 m. It is well developed on rocky shores in all parts of the country, forming part of a distinctive "orange zone", and it is also usually a common component of limestone or other calcareous rocks, again often imparting an orange or yellow-orange tinge to these substrata. At least two species are found parasitic on species of the moss Andreaea in fellfield and high-alpine rock outcrops, and there is a distinctive group of bipolar species found in high-alpine habitats. Although widely distributed and easily recognised, Caloplaca is still very much in need of serious study in New Zealand. A preliminary, "herbarium" account (Galloway 1985a: 60–70), discussed 21 species, but recent collecting and observation of the genus in the field shows that Caloplaca is much more complex here than formerly thought, and that the nature of the substratum may be of considerable importance in assigning species names as suggested by several recent Northern Hemisphere studies (see below).

Several classical accounts of the genus are fundamental to a study of New Zealand populations and include Magnusson (1944a, 1944b, 1950), Poelt (1954, 1965), Wade (1965) and Nordin (1972). Johan Santesson's account of chemistry in Caloplaca (Santesson 1970) is still an extremely useful paper [see also Steiner & Hauschild (1970) and Søchting (1996, 1997)], and the account of species with plurilocular ascospores (Hafellner & Poelt 1979) has information on C. homologa from New Zealand. Recent years have seen considerable interest in Northern Hemisphere and polar populations of Caloplaca, with important contributions coming from five separate schools: (1) the late Josef Poelt and co-workers in Graz (Poelt & Pelleter 1984; Poelt 1985; Poelt & Hinteregger 1993); (2) Ingvar Kärnefelt's school in Lund (Kärnefelt 1988a, 1988b, 1989, 1990a, 1990b, 1991, 1998, 2001, 2003; Arup 1992, 1993, 1994, 1995a, 1995b, 2006; Arup & Mayrhofer 2000; Kärnefelt & Kondratyuk 2004); (3) Ulrich Søchting's school in Copenhagen (Søchting 1973, 1989; Hansen et al. 1987a; Søchting 1992a, 1992b, 1994, 1996, 1997, 1999, 2001; Søchting et al. 1992, 2004;Søchting & Øvstedal 1992, 1998; Søchting & Olech 1995, 2000; Søchting & Lutzoni 2000, 2003; Søchting & Fröberg 2003); (4) Cliff Wetmore's North American school (Wetmore 1994, 1996, 2001, 2003, 2004a, 2004b; Wetmore & Kärnefelt 1998, 1999); and (5) the Spanish school (Navarro-Rosinés & Hladun 1996; Navarro-Rosinés et al. 2000a, 2000b, 2001). Other accounts and/or keys of the genus include: Nimis (1992), Van den Boom et al. (1998), Øvstedal and Lewis Smith (2001) and Kondratyuk et al. (2003). The atlas of British species of Caloplaca (Coppins & Fletcher 2001a–f) also contains much pertinent information. Currently, there is no world checklist or revision of the entire genus apart from the list of names produced by Cliff Wetmore [http://www.tc.umn.edu/~wetmore/AllCalop.htm]. Gaya et al. (2003) recently investigated the relationships between Caloplaca, Fulgensia and Xanthoria, using ITS sequences, and showed that all three genera are non-monophyletic. Søchting et al. (2004) accept the genus Huea C.W.Dodge & G.E.Baker some Antarctic species of Caloplaca with lecideine apothecia.

Although the present account discusses 43 species, it remains a rapid and provisional study and is not a thorough revision. Regional collecting still needs to be undertaken, especially from coastal rocks, from calcareous substrata, from living bark and dead wood, and from high-alpine habitats, before Caloplaca can be assumed to be well understood here.

Species of Caloplaca are often parasitised by lichenicolous fungi, with the following genera being known from Caloplaca in New Zealand: * Arthonia molendoi (q.v.); * Lichenodiplis lecanorae (q.v.); * Muellerella lichenicola (q.v.) and * Polycoccum rugulosarium (q.v.). A diligent search should be made for additional taxa.