Taxon classification Fungi Tremellales Tremellaceae

Tremella caloplacae (Zahlbr.) Diederich

Note.

New to Norway and to the Swedish province Torne Lappmark.

The species was at first tentatively described as Tremella sp. 1 by Diederich (1996) and eventually formally described by Sérusiaux et al. (2003). It has been reported from Austria, Canada, France, Great Britain, Greece, Greenland, and Spain (Diederich 1996, 2007, Sérusiaux et al. 2003), growing inside the hymenia, or exceptionally on the thallus, of different Caloplaca species, viz. Caloplaca arenaria, Caloplaca arnoldii, Caloplaca aurantia, Caloplaca carphinea and Caloplaca saxicola (Diederich 1996, Sérusiaux et al. 2003), and on the thallus of Xanthoria sorediata (Diederich 2007). It was recently reported as new to the Nordic countries (Thell et al. 2014) from two Swedish collections, growing on new hosts: Caloplaca decipiens (on the thallus; Fig. 1D) and Xanthoria parietina (inside the hymenium; Fig. 1E). Here it is reported on a new host ( Xanthoria elegans), in Sweden. All samples below are on Xanthoria elegans, growing inside the hymenium or on the thallus. All specimens bear two-celled basidia (Fig. 1J) and are very similar microscopically. Further investigations are needed, however, to check if all specimens growing on Teloschistaceae belong to a single species.

Specimens examined

(all on Xanthoria elegans): NORWAY. Oppland: Lom municipality, Runningsgrende, Kleive, 61°42.95'N, 8°14.05'E, 720-850 m, 29 June 2013, A. Millanes 808 (S: F-255312). - SWEDEN. Torne Lappmark: Jukkasjärvi par., Paddos, 68°19.16'N, 18°51.93'E, 625 m, 28 Aug 2013, A. Millanes 904 & M. Méndez (S: F-255313). Torne Lappmark: Jukkasjärvi par., Paddos, 68°19.13'N, 18°51.89'E, 596 m, 28 Aug 2013, A. Millanes 908 & M. Méndez (S: F-255314).