Coccotrema Müll.Arg.
Type : Coccotrema antarcticum Müll.Arg.
Description : Flora (1985: 129). See also James (1992: 214), and Messuti (1996: 57–58).
Key
Coccotrema a genus of c. 13 species (Brodo 1973; Galloway 1985a; Messuti 1996, 2002, 2003; Kirk et al. 2001; Messuti & Vobis 2003) is included in the family Coccotremataceae (Henssen 1976; David & Hawksworth 1991; Eriksson et al. 2004; Pennycook & Galloway 2004; Eriksson 2005). The ordinal position of Coccotremataceae until recently was considered uncertain (Lumbsch et al. 1994); however, recent molecular studies (Lumbsch et al. 2001a) indicate a placement in the order Pertusariales, and that the monospecific genus Lepolichen (Galloway & Watson-Gandy 1992) is congeneric with Coccotrema (Schmitt et al. 2001). Coccotrema has the following characters: Thallus crustose, dwarf-fruticose, granular, lobate or foliose. Photobiont green,? Myrmecia. External cephalodia present, containing Calothrix, Nostoc or Stigonema. Ascomata apothecia, sessile or immersed in rounded verrucae, perithecia-like with an apical ostiole; exciple pale, well-developed, with thick thalline margin. Periphysoids (sensu Henssen 1976) present or absent. Hamathecium of paraphyses, free, sometimes branched. Asci (4–)6–8-spored, cylindrical or pyriform, short, walls thickened. Ascus wall and hymenial gelatine IKI yellow, turning blue after K pretreatment. Ascospores colourless, simple, ellipsoidal, large, wall thickened, non-layered. Conidiomata pycnidia. Conidia rod-shaped. Coccotrema has a mainly circum-Pacific distribution (Brodo 1973; Messuti 1996, 2002; Messuti & Vobis 2003) with one species known in Great Britain and western Norway (James 1992; Santesson 1993). Two species are known in New Zealand.
