Lichens: Encyclopedia Arctica 5: Plant Sciences (General)

Author Stefansson, Vilhjalmur, 1879-1962


(EA-PS. Eilif Dahl)



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Ecology and Biology 2
Lichen Vegetation in the Arctic 4
Exploration of Lichen Flora 6
Lichen Floras of the Arctic Countries 12
Economic Importance of Arctic Lichens 15
Bibliography 16

EA-Plant Sciences (Eilif Dahl)

Lichens, which are compound organisms consisting of photosynthesizing algal cells growing in a protective envelope of living fungous material, are found everywhere in the Arctic where a suitable substratum exists. On the northernmost point of Peary Land they occur in abundance. Indeed, even on the Antarctic Continent, where only three species of vascular plants have been found, at least 250 species of lichens are known to occur.
Lichens are conveniently divided into two major groupings; the macrolichens and the microlichens or crustose lichens. The macrolichens are relatively large plants of varying shape. Some genera have an erect, branched thallus, which may be thread-shaped ( Alectoria , Neuropogon ), stout ( Cladonia , Sphaerophorus , and Dactylina ), or more or less flattened ( Cetraria ). The thallus is often beset with small squamules or granules ( Cladonia, Stereocaulon ). Other genera have a foil-shaped thallus attached at the center to stones (Umbilicaris), or the thallus may be closely adnate to the soil ( Peltigera , Solorina ). Still other types have a branched, flattened thallus closely pressed to stone ( Parmelia , Physcia ).
The microlichens form crusts covering rock or soil, or grow upon moss or old bones. Their most important genera in the Arctic are L i ^ e ^ cidea , Lecanora , Buellia, Rinodina , Rhizocarpon , and Caloplaca . The members of the genus Caloplaca

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often have red to orange-red colors, and one of them, C. elegans , often gives its color to the bird cliffs. Most species of microlichens are neglected by collectors who are not especially aware of them.
It is to be emphasized that the division into macrolichens and micro– lichens is no natural division but a practical one like the division of vascu– lar plants into trees and herbs.
Ecology and Biology
Lichens play an important role in arctic vegetation and in the arctic landscape. As the profuseness of other vegetation decreases toward the Poles, the importance of lichen [: ] increases because the lichens are among the hardiest of plants. As a rule, the microlichens are the most hardy ones, and their relative importance increases with colder climates.
Lichen vegetation is influenced especially by the humidity of the air. In southern West Greenland, the lichen vegetation is best developed along the shore in the middle of the fjords; toward the seacoast and toward the innermost ends of the fjords, it becomes less profuse. The same may be observed also in Spitsbergen. In the inner parts of the fjords of East Greenland, e.g., Scoresby Sound, the climate may become so dry that only a few species of lichens occur, among them desert species.
The winter minimum temperature is a factor which does not govern the distribution of lichens to the same extent as it may affect the distribution of vascular plants. To be sure, many lichen species have their distinct northern limits, but these seem to depend more upon summer warmth than winter cold. Thus, many relatively southern species are met with in Scoresby Sound in East Greenland. Scoresby Sound has for its latitude a high summer temperature, but the winters

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may be cold. Many species of lichens are, however, often of a deformed and frostbitten appearance in the Arctic, particularly Cladonia species, which in such a state may be difficult to determine. The tips of the branches are often destroyed, especially when they have been subject to the winter gales without a snow cover.
Lichen vegetation flourishes both on acid and alkaline soils and on rocks. Particularly on sandy soils, an almost pure lichen vegetation may develop, probably because of the small competition with other plants. But there are different species occurring an acid and alkaline soils; species of Solorina and Peltigera venosa especially prefer alkaline soils.
About the biology of arctic lichens, hardly anything is known. It is believed that they can carry out respiration and assimilation at some degrees below zero centigrade, but definite proof is lacking.
Experiments to determine the rapidity of growth of lichens have been carried out in Scandinavia in connection with problems of reindeer grazing. The most important food lichen, Cladonia alpestris , which occurs also in most parts of the low-arctic regions, needs more than thirty years to attain full growth. Other species grow more rapidly, e.g., Cladonia rangiferina and C. sylvatica , Cetraria nivalis and C. islandica , and especially Stereocaulon pas ^ c ^ hale . In regions heavily grazed by reindeer, Cladonia alpestris becomes subordinate in the vegetation, while Stereocaulon pas ^ c ^ hale becomes more important.
There are good reasons to believe that the rapidity of the growth of lichens decreases with a colder climate. In Peary Land, Peter Freuchen found the stone cairn built by Peary twenty years before. The stones had been moved to make the cairn, some being placed upside down, yet not much difference in the lichen vegetation or signs of new growth could be seen (according to a letter

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from Freuchen to Lynge). On the other hand, in southern West Greenland, the author has seen Eskimo graves certainly not more than thirty years old, the stones of which were covered by large lichens.
The extreme slowness of lichen growth in the Arctic has been made use of by Ahlmann (1). The glaciers around the North Atlantic Ocean had a maximum about the year 1740. Ahlmann found a zone with only scanty lichen vegetation along the “walls” bordering the glaciers in northern East Greenland for some meters above the present surface of the glaciers. He was able to connect the upper limit of this zone with side moraines most probably dating from the 1740 maximum. The lichen vegetation on the rock walls had thus not attained a mature state in the time that had elapsed since 1740. Consequently, it may be stated that specimens of lichens from the Arctic may attain a very great age.
The slowness of growth of arctic lichens makes them little resistant to solifluction. For example, where only a slight movement of the boulders of talus slopes occurs, the lichen vegetation is badly affected. Such parts of the slopes have a light color in contradistinction to the stable parts which may be dark gray because of lichens.
Lichen Vegetation in the Arctic
Vegetation types with lichens forming their chief component part are characteristic of the Arctic. The arctic prairie contains an important element of lichens, yet is rarely dominated by them. This may be due parly to the solifluction which often interferes with lichen growth. Characteristic of the prairie are the cup-shaped Cladonia pyxidata var. pocillum , C. coccifera , C. lepidota , Dactylina species, and Cetraria species. The dead parts of mosses and vascular plants are beset with microlichen species of the genera L a ^ e ^ cidea ,

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Caloplaca, and Rinodina.
The lichen health, with lichens dominating together with shrubs such as Empetrum and Betula nana or B. glandulosa , is a vegetation type of the low– arctic regions. This vegetation is probably of circumpolar occurrence and is beautifully developed in Scandinavia and southern Greenland. The lichens form a thick carpet which may be tens of centimeters thick. In places where a light snow cover occurs in winter, Cladonia alpestris is often the dominant species; in places that are more exposed to the wind, Cetraria nivalis and Alectoria s ochroleuca are dominant, mixed with Cornicularia divergens , Stereocaulon species ^ species ^ , etc.
In the snow patches lichen vegetation becomes less profuse. Some character– istic species are found, especially Solorina crocea , which is a foil-shaped, adnate species with orange coloration of the underside.
The surface components of boulder fields in the mountains and talus slopes are generally covered with lichens if the stones are stable. Most characteristic are the Umbilicariaceae, with such species as Umbilicaria cylindrica , U. probos cidea , and U. hyperborean , and Parmelias such as Parmelia pubescens , P. alpicola , and P. intestiniformis . Areas not occupied by macrolichens are generally covered with microlichens, particularly species belonging to the genera Lecidea , Lecanora , and Rhizocarpon .
The bird cliffs have a lichen vegetation of their own. On them there is an ample supply of nitrogen which stimulates a rich lichen growth on stones and rock walls. Characteristic are the red Caloplaca eleg e ^ a ^ ns , which may give color to the whole cliff, and some species of Umbilicaria ^ Umbilicaria ^ . Many species of Physcia are found, together with the red Xanthoria candelaria , and, further, Rinodina species, Lecanora melanophtalma ^ Lecanora melanophtalma ^ , ^ and other species of microlichens.^

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If no bird cliffs are found within an area, fragments of this vegetation type may be found in the birds’ resting places on top of prominent stones. The Eskimo villages also stimulate the growth of lichens and other plants.
In or near brook s , a separate type of lichen vegetation occurs, con– sisting of small microlichen species belonging to the genera Verrucaria, Staurothel s ^ e ^ , and Lecanora . The seashore is practically always devoid of lichen vegetation because of the winter ice which destroys plant life.
Exploration of Lichen Flora
Lichens have been collected in the Arctic for more than a century and a half. The lichen floras of some parts of the Arctic are fairly well known, whereas other parts are unexplored. Many arctic expeditions bring home collections of lichens, but the size and quality varies according to the ability of the collectors. Naturally the collection of a trained lichenologist is far better than that of an amateur, or of a botanist who has not made lichen– ology his specialty. In every area there are some common species dominating the lichen s vegetation, and these are collected by everybody. Many species occur as occasional specimens among the common ones which they may superfi– cially resemble; these are naturally collected only by the trained lichenologist. The collections not made by specialists may give interesting information about lichen floras of areas not previously explored, but a representative collection can be made only by a man who knows the lichens. A fairly representative collection of macrolichens may be made by anyone who devotes some time and interest to the task, but he will always miss many species of microlichens.
The procedure for collecting arctic lichens is very simple. The lichens, or pieces of stones with attached lichens, are merely wrapped in a piece of

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paper and dried. They must be carefully labeled. In this state they may be kept for years until they can be unpacked at home, pressed if necessary, and classified. The identification of the lichens must be left to the lichenologist who has at his disposal the necessary literature and specimens for comparison.
The last attempt to make a survey of the lichen flora of more than a single major part of the Arctic was made by Fries (11). His Lichenes Arcto ^ i ^ contains descriptions (in Latin) of the lichens considered, and is based on collections from Scandinavia, Bear Island, Spitsbergen, Iceland, Greenland, and Kola Peninsula. It is still of great value.
To give an account of our knowledge of the lichen flora of the Arctic, it is necessary to treat the different areas separately. Extensive references to literature on arctic lichens are given by Lynge (28, 29).
Northern Scandinavia and Kola Peninsula . Large collections have been made in northern Norway, northern Sweden, and especially in northern Finland. The results have been published in many papers by Nylander (35); Th. Fries (11, 12);; his Lichenographia Scandinavica (13) also contains descriptions of the species, but was unfortunately never completed); Wainio (37, 38; his Lichenographia Fennica (39) contains descriptions of the lichen species in question, but was likewise never completed); Lynge (15-32); Magnusson, Räsänen, and others. Our knowledge of the lichen flora of Kola Peninsula is scanty.
Novaya Zemlya . Large collections were made by Lynge who visited the middle part of the island and the western coast in 1921. Some minor collections have been made by Swedish and Soviet expeditions. The results of the expedition of 1921 are published by Lynge (25), with references to older literature.
Arctic Siberia. Little is known of the lichen flora of the western and

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central parts of arctic Siberia, and any additions are of interest. In 1876, M r . Brenner collected lichens along the Yenisei River during an expedition with A. E. Nordenskiold; he also found some specimens at the mouth of the river. The collections are being studied by Magnusson, but the results have ^ thor: y recent publications? ck oughout rticle ^ not yet been published. The Maud expedition collected a few lichens which have been identified and described by Lynge (31).
On the famous Vega expedition, the surgeon E. Almquist collected lichens in the few places visited. The visits were too short to permit extensive collecting, but Almquist was an excellent observer who made the utmost of the opportunity. A preliminary survey of the results is given by Almquist (3); later the collections were studied and described by Malme (34). At Pitlekai in easternmost Siberia, the Vega expedition was caught by the ice and forced to stay for the winter. During this period Almquist had a good opportunity to collect lichens, although snow covered the area during the greater part of the stay. These lichens have been described by Wainio (38).
Soviet expeditions have perhaps collected lichens along the Siberian coast, but nothing has been published as far as the author knows, apart from some stray contributions by Savich and Oxner.
Bering Strait Area . After the winter in Pitlekai, the Vega expedition proceeded to Bering Strait. Some places on both sides of the strait were visited and Almquist made good collections, which were studied and described by Nylander (35). Almquist (2) has also given a picture of the lichen vege– tation of the area.
Kamchatka . In 1912-14, the Russian lichenologist Savich visited Kamchatka and made large collections. Unfortunately only a few of the lichen genera l from the area have been identified and the results published (36). A collection of

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lichens containing 102 different species was brought home by Hult e ^ é ^ n from Swedish Kamchatka expeditions; these have been described by Du Rietz (10).
Alaska and Canadian Western Arctic . Our main source by knowledge of the Alaskan lichen flora is the work by Cummings (6); this work is based on ^thor O.K?^ collections from many expeditions. Up until 1949 when George Flavo was in Alaska, no trained lichenologist ever visited the area. The principles of lichen systematics employed by Cummings are not in accordance with those now followed, and a revision seems desirable. In any case most of the material comes from the subarctic part of Alaska, not from the northern arctic part.
A number of stray contributions [: ] to the study of lichen flora of Alaska and the Canadian Western Arctic have been published by different authors (Degelius, Herre, Howe, Lynge, Magnusson, Merrill ^ ) ^ . Unpublished descriptions are probably to be found in American herbaria.
Canadian Eastern Arctic . Several expeditions have collected lichens in the Canadian Eastern Arctic, but no trained lichenologist has ever visited this immense area, so our knowledge is still incomplete.
The Second Norwegian Arctic Expedition in the Fram brought home good collections from Ellesmere Island and adjacent areas. The collections, which contained approximately 160 species, have been described by Darbishire (9). The classifications need a modern revision. The Danish Fifth Thule Expedition of 1921-24 brought home many lichens from the Arctic Archipelago and the adjacent mainland. The collections, containing approximately 100 different species, have been studied by Lynge (18).
Prof. N. Polunin made good collections in Baffin Island and adjacent areas in 1931, 1934, and 1936. The collections, which contained 166 species, have been described by Lynge (17). The publication also contains numerous references

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to previous finds. Farther Arth e ^ è ^ me Dutilly also has made collections within the same area. The collections, which contained 88 species, were studied by Lynge (15).
Labrador . Almost nothing is known about the lichen flora of most of Labrador. Some records are found in Macoun (33). A small collection from Hebron was brought home by Tanner, but its description has not yet been [: ] published.
Greenland . We are fairly well informed about the lichen flora of most parts of Greenland. The most extensive collections are found in the herbaria of Copenhagen and Oslo, some collections being also in Stockholm. The last attempt to make a complete survey of the lichen flora of Greenland was by Branth and Grønland (5) and Branth (4), comprising material from the Danish expeditions up to 1892. The classifications need a modern revision.
North Greenland was visited by Th. Wulff in 1917, and his collections, which contained 64 species, have been described by Lynge (19). The Danish Peary ^ ^ l ^ L ^ and Expedition (1948-49) also collected some lichens in this area.
West Greenland has been visited by many expeditions. Jens Vahl traveled in West Greenland and also in the southernmost part of East Greenland during 1 9 ^ 8 ^ 28-36. His collections were made with great care and profound knowledge of lichens, and still form an important basis for our information. In 1871, the famous Swedish lichenologist Th. M. Fries visited the Disko area. His collections have been studied and described by Lynge (27). In 1946, the Danish lichenologist M. Skytte Christiansen visited the Holsteinsborg area and some other places in West Greenland, but his collections are not yet described. In 1937, E. Dahl traveled in the southern part of the Frederikshaab District and in Julianshaab District in southernmost Greenland. The macrolichens have been studied (7), but

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the microlichens have not so far been examined. Besides these major collections, quite a number of minor collections have been made, mostly by Danish expeditions.
East Greenland has also been visited many times. Farthest to the north, the Danmark ^ Danmark ^ E^e^xpedition collected lichens, and the results have been described by Galløe (14). In 1929, Lynge, and in 1930, Scholander, visited northern East Greenland. Reports have been published by Lynge and Scholander (32) and by Lynge (24).
Minor collections have been made in the district between Scoresby Sound and Angmagssalik and descriptions have been published by different authors (Wainio, Lynge, Lamb). Southern East Greenland has been visited by Danish and Norwegian expeditions. Scholander collected lichens in the district in 1932, and the results have been described by Dahl, Lynge, and Scholander (8).
Jan Mayen was visited by the Norwegian botanist Johannes Lid, in 1930, and by Lynge, briefly, in 1929. The results have been published by Lynge (23).
Iceland . Lichens have been collected for a long time in Iceland, in earlier times chiefly by Danish expeditions. Good collections are kept in Copenhagen and in Reykjavik. In 1937 and 1939, Lynge made extensive studies in Iceland. The macrolichens from Lynge’s collections have been described by him (22), and here references to older literature are also found. Unfortunately it was impossible for him to revise older collections. The microlichens were mostly identified by the time of Lynge’s death in 1942, but descriptions have not yet been published.
Spitsbergen . Spitsbergen has been visited by many expeditions which collected lichens; in older times these were mostly Swedish, in recent times mostly Norwegian. The results of the Swedish expeditions have been published by Th. Fries (12). The western coast has been visited by Lynge, Lid, and H o ^ ø ^ eg; the northern coast by Høeg’ Scholander, and Dahl; and the east coast by Dahl. The results

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of these collections of the macrolichens of the west and north coasts have been published by Lynge (26), where references to older publications and finds also are to be found. In this work Lynge also gives an enumeration of the macrolichen species known from Novaya Zemlya, Spitsbergen, and West and East Greenland. Large collections of microlichens and considerable collections of macrolichens still await study and publication.
Franz Josef Land was visited by a Norwegian expedition in 1930. The results have been published by Lynge (20). Altogether 94 species are known from the archipelago.
Bear Island was visited by Th. Fries in 1868, and his extensive collections have been described by Lynge (21).
Lichen Floras of the Arctic Countries
The number of macrolichen and microlichen species at present known from those arctic regions from which fairly good information is available is given in Table I. The figures are only approximate. Different authors may have different

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Table I.
Locality Number of macrolichens Number of microlichens Reference
Novaya Zemlya 140 316 (25, 26)
Pitlekai 76 162 (38)
Bering Strait 116 288 (35)
West Greenland 205 240 (7, 27)
East Greenland 142 270 (24, 32)
Jan Mayen 60 84 (23)
Iceland 151 -- (22)
Spitsbergen 145 -- (26)
Bear Island 54 131 (21)
concepts of the species and doubts concerning the reliability of older records may arise. Naturally many of the figures will increase with future exploration.

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As a general rule one may state that in regions which have been fairly well explored (Novaya Zemlya, East Greenland, Bear Island), somewhat more than twice as many microlichens as macrolichens are found. West Greenland and Spitsbergen are well explored, but considerable collections of microlichens have not so far been examined. For comparison it can be stated that from the Nordic countries (Finland, Denmark, Norway, and Sweden) approximately 460 species of macrolichens and 1,300 species of microlichens are known.
If we try to make phytogeographical comparisons of the lichen floras of the arctic countries, one difficulty is met with at once: the lichen floras of Siberia, western North America, and the American mountain ranges are too insuffi– ciently known. An investigation of, for example, the Bering Strait area by a competent lichenologist is most desirable.
Despite this, our present knowledge of the macrolichen flora of many arctic countries seems to be sufficient to permit some conclusions as to the character of their lichen floras. Some of these problems have been treated by Lynge (16, 26, 30).
The arctic lichen flora doubtless contains elements of great age. Possibly they lived in arctic regions before the Quaternary glaciations. As examples of such types may be chosen Neuropogon sulphureus (see Fig. 2) and Dactylina arctica ^ . ^ (see Fig. 3). Of these, N. sulphureus , which is a characteristic lichen readily recognized even by the amateur, is of special interest. It has never been met with in subarctic countries but exhibits a bipolar type of distribution, occurring again ^ in ^ the Southern Hemisphere with many related species. Bipolar types of dis– tribution are by no means rare among lichens.
The macrolichen species of arctic countries are generally of a wide distri– bution and found within many countries. Circumpolar types of distribution are

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common. Within each country the species may, however, be of a peculiar local occurrence, suggesting that they may be interglacial relics (e.g., in Spitsbergen, see 26).
The microlichen species within the arctic countries seem generally to have a more restricted distribution than the macrolichens. There are more endemics of various arctic countries among microlichens than among macrolichens (16).
An element characteristic of the Bering Strait area is spreading into Siberia and Arctic America (examples are Cetraria richardsonii , C. chrysantha , Pilophoron aciculare , and Spereocaulon intermedia ).
There seems to be a close relationship between the macrolichen floras on both sides of the Atlantic Ocean. Thus there are very few species of macrolichens in Spitsbergen which are not found in East Greenland, and more than 95% of the macrolichen flora of southern West Greenland is also found in Scandinavia (7). It is impossible to say that they do not occur in the Bering Strait area, as this region is insufficiently known. But it may be stated that there is a closer relationship between the southern West Greenland macrolichen flora and the Scandinavian alpine lichen flora than there i is between the alpine lichen floras of Scandinavia and the Alps.
It seems probable that even dominating elements of the lichen floras of many arctic countries survived the last glaciation, possibly they lived there also during earlier glaciations. This could be explained by the extreme hardiness of lichens, which makes them able to survive unfavorable periods better than other groups of plants. A closer study, especially of the distribution of the microlichen species, may reveal old phytogeographical relationships of the different parts of the Arctic.

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Economic Importance of Arctic Lichens
Lichens have considerable economic importance especially in the low-arctic regions, because they serve as a basic food for the reindeer, especially as winter fodder. This is indicated by the manner in which, if an area is too densely populated with reindeer, as ma [: ] happen in northern Scandinavia, the lichen vegetation changes. The fodder lichens most important to reindeer are Cladonia alpestris , Cetraria nivalis , and Stereocaulon paschale , besides some related species. Cetraria nivalis have a particularly high percentage of digestible carbohydrates. [: ]
Lichens may serve as emergency food for man. Most famous is Cetraria islandica (Iceland moss, pig moss, food moss), which has served as a substitute for flour during hard times in Scandinavia and Iceland. It has also served as food for pigs. It, too, contains a high percentage of digestible carbohydrates.

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1. Ahlmann, H.W. “Studies in North East Greenland, 1939-40,” Geografiska Ann ., Stockh. pp.145-209, 1941.

2. Almquist, Ernst. “Die Lichenenvegetation der Küsten des Beringsmeeres,” Nordenskiőld, A.E. Vega-Expeditionens Vetenskapliga Iakttagelser Vol. 4. Stockholm, Beijer, 1887, pp.409-42.

3. ----. “Lichenologiska iakttagelser paa Sibiriens Nordkust,” Ibid . ^ Vol. 1, ^ Stockholm, Beijer, 1882, pp.195-222.

4. Branth, J.S. Deichmann. “Tillaeg til Grønlands Lichen-Flora,” Medd . Grønland vol.3, pp.750-62, 1892.

5. ----, and Grønland, Chr. “Grønlands Lichen-Flora,” Ibid . vol.3, pp.447-513, 1887.

6. Cummings, Clara E. “The lichens of Alaska,” Cardot, J., Cummings, C.E., and others. Cryptogamic Botany . Wash., D.C., 1910, pp.65-149, ^ Harriman Alaska Ser. vol.5 ^ .

7. Dahl, Eilif. “Studies in the macrolichen flora of South West Greenland,” Medd. Grønland 1948. (In press)

8. ----, Lynge, B., and Scholander, P.F. Lichens from Southeast Greenland . Oslo, Dybwad, 1937. Norsk Polarinstitutt Skrifter Nr. 70.

9. Darbishire, Otto V. Lichens Collected During the 2nd Norwegian Polar Expedition in 1898-1902, and Determined by Otto V. Darbishire . Kristiania, Brøgger, 1909. Report of the Second Norwegian Arctic Expedition in the “Fram” 1898-1902, no.21.

10. Du Rietz, G.E. “The lichens of the Swedish Kamtchatka-Expeditions,” Arkiv főr Bot . vol.22 A, no.13, pp.1-25, 1929.

11. Fries, Th.M. “Lichenes Arctoi Euroae Groenlandiaeque Hactenus cogniti,” Vetenskaps-Soc.Upsala Nova Acta Ser. III, vol.3, pp.103– 398, 1861.

12. ----. “Lichenes Spitsbergenses,” Svenska Vetenskapsakad. Handl . vol.7, no.2, pp.1-53, 1867.

13. ----. Lichenographia Scandinavica. Vol. I, Archilichenes Discocarpos Continens . Upsala, Berling, 1871-74, 1 vol. in 2.

14. Galløe, Olaf. “Lichens from North-East Greenland (N. of 76° N.Lat.) collected by the “Danmark-Expeditionen’ 1906-8,” Medd.Grønland vol.43, no.9, pp.181-91, 1910.

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15. Lynge, Bernt. A Contribution to the Lichen ^ è ^ Flora of Canadian Arctic . Collection of Father Artheme Dutilly e.m.i. naturalist of the Arctic Missions . Wash., D.C., Catholic University of America, 1939.

16. ----. “General results of recent Norwegian research work on arctic lichens,” Rhodora vol.36, pp.133-71, 1934.

17. ----. “Lichenes,” Polunin, Nicholas, comp. Botany of Canadian Eastern Arctic. Part II. Thallophyta and Bryophyta . ( Montreal, ^ Ottawa, ^ 194 6 ^ 8 ^ ) Nat.Mus.Can. Bull . no.97. Biological Series no.26.

18. ----. Lichens Collected During the Danish Fifth Thule Expedition Through Arctic Canada . Copenhagen, Gyldendalske, 1937. Thule Expediti^o^n, 5th, Report 1921-24. Report vol.2, no. 3. ^^

19. ----. “Lichens collected on the North Coast of Greenland by the late Dr. Th. Wulff,” Medd.Grønland vol.64, pp.279 / ^ - ^ 88, 1923. ^^

20. ----. Lichens Collected on the Norwegian Scientific Expedition to Franz Josef Land 1930. Oslo, Dybwad, 1931. Norsk Polarinstitutt Skrifter Nr. 38.

21. ----. Lichens from Bear Island (Bjørnøya) . Oslo, Dybwad, 1926. Norsk ^^ ^^ ^^ Polarinstitutt Skrifter Nr. 9.

22. ----. Lichens from Iceland Collected by Norwegian Bo [: ] anists in 1937 and 1939 . Oslo, Dybwad, 1940. Norske Videnskaps-Akad. I. Mat. -Nat.Kl. Skrifter vol.7 no.7, 1940.

23. ----. Lichens from Jan Mayen . Oslo, Dybwad, 1939. M ^ N ^ orsk Polarinstitutt ^^ Skrifter Nr. 76.

24. ----. Lichens from North East Greenland . Oslo, Dybwad, 1940. Ibid . Nr.81.

25. ----. Lichens from Novaya Zemlja . Oslo, Brøgger, 1928. Norwegian Expedition to Novaja Zemlya 1921. Report of the Scientific Results . No.43.

26. ----. Lichens, from the West and North Coasts of Spitsbergen and the North-East Land Collected by Numerous Expeditions. I. The Macrolichens . Oslo, Dybwad, 1938. Norske Videnskaps– Akad. I. Mat. -Nat. Kl. Skrifter no.6, 1938.

27. ----. Lichens from West Greenland Chiefly Collected by Th. M. Fries . Copenhagen, Reitzel, 1937. Medd.Grønland vol.118, no.8.

28. ----. On Dufourea and Dactylina. Three Arctic Lichens . Oslo, Dybwad, 1933. Norsk Polarinstitutt Skrifter Nr. 59.

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29. ----. On Neuropog on Sulphureus (Kőnig) Elenk., a Bipolar Lichen . Oslo, Dybwad, 1941. Norske Vide sn ^ ns ^ kaps-Akad. I. Mat. –Nat.Kl. ^^ Skrifter 1940, no.10.

30. ----. “On the survival of plants in the Arctic,” Norsk Geogr.Tidsskr . B. 7, 1938/39, H.5-8, pp.233-41.

31. ----. Vascular Plants and Lichens . Bergen, Grieg, 1929. Maud-Ekspeditionen, 1918-1925. Scientific Results vol.5, no.1.

32. ----, and Scholander, P.F. Lichens from North East Greenland, I . Oslo, Dybwad, 1932. Norsk Polarinstitutt Skrifter Nr. 41.

33. Macoun, John. Catalogue of Canadian Plants. Part VII. Lichens and Hepaticeae . Ottawa, Govt.Printing Bur., 1902.

34. Malme, Gust.O.A:n. “Lichenes orae Sibiriae borealis inde ab insula Minin usque ad promotorium Ryrkajpia in expedition Vegae lecti,” Arkiv főr Bot . B.25 A, H.1, N:o 2, 1932.

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Eilif Dahl