Notes on Arthrorhaphis and its lichenicolous fungi in Greenland

The taxa of the genus Arthrorhaphis in Europe and Greenland have previously been revised by Obermayer (1994). Ihlen (1998) treated the Norwegian taxa. Three species-Arthrorhaphis alpina, A. citrinella, and A. vacillans-all of them yellow-colored due to the occurrence of rhizocarpic acid, were recogn ized for Greenland. The last-mentioned species (syn. Bacidia anziana Lynge) has also been discussed by Lynge (1940) and Hansen and Poelt (1987). A map outlining the distribution of Arthrorhaphis vacillans and A. alpina in the American Arctic has recently been presented by Thomson (1998) With the int ention of mapping the Greenland occurrences of these species in detail, we investigated the available material. The four non-yellow (rhizocarpic acid lacking) species of Arthrorhaphis, A. aeruginosa R. Sant. & Tonsberg, A. grisea Th. Fr., A. muddii Obermayer, an d A. olivacea R. Sant. & Tonsberg have so far not been found in Greenland.