Cladonia P.Browne
Type : Cladonia subulata (L.) F.H.Wigg. [=Lichen subulatus L.]
Description : Flora (1985: 100). See also Archer (1992b: 111), Ahti (2000: 82) and Ahti & Hammer (2002).
Key
Cladonia is a genus of c. 450 known species in the family Cladoniaceae (Kirk et al. 2001; Stenroos et al. 2002a; Eriksson et al. 2004; Pennycook & Galloway 2004), widely distributed in both Northern and Southern hemispheres. Cladonia is the most highly speciose lichen genus in New Zealand with some 70 taxa currently recognised. The first relatively modern treatment of New Zealand species of Cladonia was that of Sandstede in Zahlbruckner (1941: 324–328) based largely on collections made by H.H.Allan and J.S. Thomson in the 1930s. Carroll Dodge's account of subantarctic taxa in the Cladoniaceae (Dodge 1948) is a neglected but still useful treatment, dealing with taxa from the subantarctic islands. In the 1950s William Martin took up Cladonia in earnest, making extensive collections from many parts of the South I. (Martin 1958: 607). His identifications (Martin 1958) were based in large part on the work and assistance of the Yale lichenologist, A.W. Evans (who placed New Zealand material sent to him by Martin, in mainly Northern Hemisphere names), but he later added several new taxa of his own (Martin 1962). These initial accounts, Dodge aside, failed to recognise New Zealand as an area of much endemism or speciation in Cladonia, the observed variation in the large collections made between 1926 and the 1960s resulting in recognition of many infraspecific taxa of mainly Northern Hemisphere names. For additional notes on the genus in New Zealand see Galloway (1985a: 100–124), but this account too has many deficiencies and is not a reliable guide to species identification of taxa now known to be present here.
Recent taxonomic work on Cladonia from the Northern Hemisphere, Australia, North and South America, Antarctica and the subantarctic shelf islands has clarified the identity and distributions of many taxa that also occur in New Zealand and the following accounts are of relevance to any study of New Zealand populations (Ahti & Kashiwadani 1984; Archer 1985a, 1985b, 1986a, 1986b, 1988, 1989, 1992b; Archer & Bartlett 1986; Stenroos 1986, 1988a, 1989, 1993; Ahti et al. 1990; Stenroos & Ahti 1991; Stenroos & Smith 1992; Hammer 1993b, 1995a, 1995b, 1996a, 1996b, 1996c, 1996d, 1996e, 1997a, 1997b, 1998a, 1998b, 1999, 2000, 2002, 2003a, 2003b; Hyvönen et al. 1995; Ahti 1997, 2000; Stenroos et al. 1997; Øvstedal & Lewis Smith 2001; Ahti & Hammer 2002; Stenroos et al. 2002b, 2002c; Litterski & Ahti 2004; Ahti & De Priest 2005). Chemistry in Cladonia is reviewed in Huovinen et al. (1990).
Molecular studies (Hyvönen et al. 1995; Stenroos et al. 1997, 2002b; Stenroos & De Priest 1998a; De Priest et al. 2000) indicate that taxa formerly included in the genus Cladina Nyl. (e.g. Hale & Culberson 1970; Brodo 1976; Ahti & Lai 1979; Follmann 1979; Ahti 1984, 2000; Ahti & Kashiwadani 1984; Galloway 1985a; Stenroos 1988b, 1993; Beard & De Priest 1996; Ahti & De Priest 2001) are best kept within Cladonia, a procedure followed in this account. Recent molecular studies (Stenroos et al. 2002a, 2002b, 2002c) have led to a reappraisal of infrageneric taxonomy within Cladonia, their results not supporting current sectional classification. Stenroos et al. (2002a) propose a new preliminary classification of Cladonia and distinguish three informal subdivisions. Within these subdivisions four supergroups and, further, seven groups and two subgroups are distinguished (Stenroos et al. 2002a: 251), and no doubt this arrangement will change again once the remaining 300 taxa are analysed and a world monograph is achieved. In anticipation of this, parts of the proposed monograph are being made available online as regional treatments are consolidated (see Stenroos et al. 2002c).
What has severely frustrated local studies of Cladonia, to a very large extent, is a comprehensive knowledge of the variation of Northern Hemisphere taxa in order to be sure which of the species present in New Zealand are truly cosmopolitan, and which are more regional or local in their distribution. We have been singularly fortunate in recent years to have a Northern Hemisphere Cladoniologist take a detailed interest in species of Cladonia in New Zealand. Since January 1999, Prof. Samuel Hammer (Boston University) has made several visits to New Zealand (supported by grants from the National Science Foundation PEET Programme, and from the National Geographic Society) specifically to study the family Cladoniaceae, in the field and in the herbarium, as part of a wider study of morphological development, speciation and phylogeny of the family in the Southern Hemisphere. It is more highly diversified in the Southern Hemisphere than it is in the Northern Hemisphere, and may reflect a Gondwanan origin of the group. He has patiently worked through large unidentified Cladonia collections of H.H. Allan, J.K. Bartlett, J. Child, P. Child, D.J. Galloway, W. Martin and J.S. Thomson and revised the named collections in AK, BM, CHR, OTA and WELT and this, together with his extensive field knowledge of the genus in New Zealand from Fiordland to Northland, has given him an unrivalled overview of this genus in a local context. The present account is based on his published accounts as well as on collaborative work with him in the field and the herbarium, and he also prepared the revised key to species.
