SOMMERFELTIA 33 (2009) 3 Øvstedal, D. O., Tønsberg, T. & Elvebakk, A. 2009. The lichen flora of Svalbard. – Sommerfeltia 33: 1−393. ISBN 82-7420-029-2. ISSN 0800-6865. 742 species, including 151 reported for the first time, are treated from Svalbard (exclusive of Bjørnøya). New to science are: Bryocaulon hyperborea Øvstedal (also known from Greenland), Buellia insu- laris Øvstedal, Lepraria svalbardensis Tønsberg, Placynthium pulvinatum Øvstedal (also recorded from mainland Norway), Rhizocarpon dahlii Øvstedal, R. tephromelae Øvstedal, and Tephromela lucifuga Øvstedal & Tønsberg. New combinations are: Aspicilia major (Lynge) Øvstedal, Aspicilia punctiformis (Lynge) Øvstedal, Cetraria racemosa (Lynge) Øvstedal, Miriquidica picea (Lynge) Øvstedal, and Stereocaulon compactum (I. M. Lamb) Øvstedal. Information on morphology, anatomy, chemistry, substrate preferences and distribution is included for all taxa. Keys to genera and species are provided. Separate keys are provided for sorediate species on rock and on soil/bryophytes. 6 % of the species are defined as cosmopolitan. More than one third has a bipolar distribution, whereas about 60 % are restricted to the Northern Hemisphere, 52 species are high-arctic and lacking from Fennoscandia, and 12 species are at present known as Svalbard endemics. Keywords: Ascomycetes, Bacidiomycetes, Lichens, Arctic, Svalbard, Flora, Taxonomy. Dag Olav Øvstedal and Tor Tønsberg, Museum of Natural History, University of Bergen, Allégaten 41, P.O. Box 7800, N-5020 Bergen, Norway. Arve Elvebakk, Tromsø University Museum, University of Tromsø, N-9037 Tromsø, Norway. 28 SOMMERFELTIA 33 (2009) INTRODUCTION Svalbard means “the land with the cold coasts”, and the land is indeed cold, with winter temperatures often below −20 ºC, and with plant life struggling to survive. Perhaps the most successful group is the lichens. They occur in most habitats, from sea-level to the highest peaks, and are most colourful constituents of some plant communities. Already the earliest botanical expedition to Svalbard, that of Phipps in 1773 (Lynge 1938) had a list of 11 lichens. However, identifying Svalbard lichens has often been a challenge, as there has been no flora with keys and descriptions for the arctic part of Europe including Svalbard. The checklist of Elvebakk & Hertel (1996) was a great inspiration and starting-point for this work, and we have built much of our research around that study. In our days the climate is rapidly changing, especially in arctic areas, creating problems for much of the biota found there. This makes it urgent to understand and document the biodiversity found there before major changes occur, and we hope that the present study will be a help for future researchers studying changes in the Svalbard lichen flora. Also, a correct naming of the organisms is necessary for ecological, physiological and biogeographical studies. However, no work of this kind is ever really finished, due to the continuing process of im- migration and extinction, and also to our limited understanding of some species groups. After us, there will be a deluge of molecular data which hopefully will help with this understanding. Also, even after some 230 years of lichenological research on Svalbard, new major collections rarely fail to produce additional taxa. This introduction would not be complete without a homage to the great expert on arctic lichens, Bernt Lynge (1884−1942). It is a great pity that he never finished his study of Svalbard lichens. We have had access to innumerable herbarium specimens collected by him, many of them bearing his comments. However, there is one problem regarding both his and other collections: nothing is usually indicated about the ecology of the specimens. Since the present authors only have limited first-hand knowledge of most of the species’ ecology, we have not been able to give as much information about this aspect as we would have liked to. The history of lichenological investigations on Svalbard up to 1938 is found in Lynge (1938) and from 1938 to 1996 in Elvebakk & Hertel (1996). SOMMERFELTIA 33 (2009) 29 MATERIALS, METHODS, CIRCUMSCRIPTION OF THE AREA, AND TERMINOLOGY MaterialS The major part of the material examined is from the herbarium of the University of Oslo (O), where the collections of Lynge from his expedition to Svalbard in 1926 are deposited. Lynge published his study about the macrolichens (Lynge 1938), but most of the microlichens were not treated. This large material has now been studied and determined for this flora treatment, mostly by the first author. Lynge also had available much of the material collected by Th.M. Fries in Svalbard in 1868. This material is still in Oslo and has been available to us. Also O material from J. Lid, who visited Svalbard in 1920, and parts of the collections by O.A. Høeg, who was there in 1928, have been studied. Another great collector, Eilif Dahl, visited Svalbard in 1936, and most of his lichen collections are at O. Also a small, but important collection made by R. Haugan in 2002 is found in O. Some of Lynge’s collec- tions were distributed to the other University herbaria in Norway (BG, TRH, TROM). Bergen (BG) houses collections made by T. Tønsberg in 1986, 2002 and 2003, especially Lepraria spp. and sorediate crustose lichens in general. In Trondheim (TRH), much of the material collected by O.A. Høeg in 1928 and determined by Lynge is deposited, in addition to a small but important collection by A. A. Frisvoll. In Tromsø (TROM), large collections by A. Elvebakk, partly also from his students, are deposited. The material from various Swedish expeditions, with the exception of most of Th.M. Fries’ 1868 material, is found at UPS or S. The materials from Poulsen’s and Summerhayes and Elton’s expeditions are supposed to be placed in BM, but we have not been able to obtain any of their lichen collections from Svalbard. Important collections made by Polish researchers in Svalbard are located in Krakow (KRA, KRAM), mostly from the Hornsund and Sørkapp areas, and many of these have been on loan and restudied by us. The important Svalbard collections in München (M) published by H. Hertel have only partly been restudied by us. A number of additional botanical expeditions to Svalbard have also collected lichens, but it has been impossible to search for all these, which in many cases have not resulted in any published lists of lichen species. Lichenicolous, non-lichenized fungi are not included in the present treatment. METHODS Microscopical details were obtained by examining hand-cut sections, squashed material and, oc- casionally, freezing microtome sections. Measurements given in mm are dissecting microscope measurements on dry material, whereas those given in µm are compound microscope measurements in water (sometimes with a drop of 10 % KOH added). Chemical spot tests on thallus have mostly not been used as they sometimes may be misleading, and often not exact enough for our purpose, but have in some cases been performed: 10 % KOH (K), 30 SOMMERFELTIA 33 (2009) 50 % HNO3 (N), Modified Lugol’s solution (where water was replaced by 50 % lactic acid and the solution added after pre-treatment with KOH (K/I), iodine solution (iodine crystals dissolved in 70 % etanol) (I), paraphenylendiamine saturated solution in 96 % ethanol (P) or commercial hypochlorite solution (C). Thin-layer chromatography (TLC) has been performed on collections extensively in accord- ance with the standard methods of Culberson & Kristinsson (1970) and Culberson (1972), modified by Menlove (1974) and Culberson & Johnson (1982) for the determination of lichen compounds. In general, solvents A and B were used, in selected cases also solvent C. Fatty acids, which require glass plates to be detected, were not generally studied. Most specimens collected by T. Tønsberg and all specimens of Lepraria in addition to selected specimens of Placopis and Sporastatia, as well as all cited isidiate and sorediate specimens were chromatographed in all three solvents using glass plates at least in solvent C to allow for the detection of fatty acids; specimens in which fatty acids were de- tected, were usually re-run on glass plates in all three solvents. High-pressure liquid chromatography (HPLC) was performed on a few specimens by J.A. Elix. CIRCUMSCRIPTION OF THE AREA The area for the flora comprises the Svalbard archipelago with the exclusion of Bjørnøya and is situ- ated between 76°28’ and 80°41’ northern latitudes and between 10° and 35° longitudes east. TERMINOLOGY Geographical names follow ‘The Place Names of Svalbard’ (Anonymous 2003). However, under Specimens seen names are written according to the herbarium labels, whereas names in current use (if deviating) are given in brackets. It should be noted that Spitsbergen is not a synonym of Svalbard, but is the largest island of the archipelago. DISTRIBUTION INFORMATION The Svalbard Lichen Database (SLD, http://www.nhm.uio.no/botanisk/lav) hosted by the University of Oslo, at present includes collections from O, BG and TROM, and is under development. World distribution patterns are indicated, based on a number of floras and updated web check- lists, particularly from Fennoscandia (Santesson et al. 2004), North America (Esslinger 2008), Chile, including its claimed Antarctic territory (Galloway & Quilhot 1998), Argentina (Calvelo & Liberatore 2002), Australia (McCarthy 2008), New Zealand (Galloway 2007), and Antarctica (Øvstedal & Lewis Smith 2001). Species occurring in subantarctic islands are most often lumped with Antarctica. Distributions within the Arctic are briefly cited. For a more detailed survey, consult the Pan- arctic Lichen Checklist (Kristinsson et al. 2006) at http://archive.arcticportal.org/276/01/Panarctic_li- chen_checklist.pdf, which indicates presence/absence within 31 sectors of the Arctic. SOMMERFELTIA 33 (2009) 31 DESCRIPTION OF THE AREA TOPOGRAPHY Svalbard is dominated by mountains, glaciers and strandflats. The mountains are often steep, with spectacular peaks, but where the layers are horizontal, table-mountains are found. The northern and western fjords are deeply indented by steep-sided fjords, and the two largest ones, Isfjorden and Wijdefjorden, nearly divide Spitsbergen in two parts.