PHYTOGEOGRAPHY OF GREENLAND IN THE 

 LIGHT OF RECENT INVESTIGATIONS 



Tyge W. Bocher 



Institute of Plant Anatomy and Cytology, University of Copenhagen, Copenhagen, 



Denmark 



Greenland is undoubtedly the most important working field for Danish 

 botanists. Its phytogeography has always been of international importance. 

 Although our present knowledge is comparatively large, new problems seem 

 continuously to arise. The phytogeographical work going on is partly 

 floristic, partly ecological or palynological (Bocher, 1954, 1963; Bocher and 

 Laegaard, 1962; Fredskild, 1961; Holmen, 1957; Iversen, 1953; Schwarzen- 

 bach, 1961; Sorensen, 1953). Parallel to the field investigations, the species 

 that are the bases of all phytogeographical discussion are examined separately 

 by means of experimental cultivation and cytological studies. The survey 

 given below of the phytogeography of Greenland deals primarily with the 

 floristic problems; a few particularly important questions about the vegeta- 

 tion will also be touched. 



In Greenland there are now known about 500 native vascular plant species 

 of which about 50 per cent are circumpolar; about 1 14 species have their main 

 area west of Greenland and 82 east of Greenland, whereas 35 (mostly apo- 

 micts) are endemic. Southwest Greenland is richest in species, having 335 

 native taxa, but even in northernmost Greenland the flora comprises 101 

 species (for further details see Bocher, Holmen and Jakobsen, 1957, 1959; 

 Holmen, 1957). 



It has been possible to divide Greenland into a number of natural floristic 

 provinces and districts which are shown in Fig. 1 . Their boundaries are placed 

 along the area-limits of 282 species whose distribution has been mapped 

 (see Bocher, 1938, 1963). The most important floristic boundary is undoubted- 

 ly that cutting off the provinces SW.-S.-SE. from the rest. This boundary 

 has been studied since 1932, and as it seems to have more than local importance, 

 it will be dealt with in some detail. 



One of the main results of the early studies in middle east Greenland 

 (Bocher, 1933, 1938) was a demonstration of a distinct floristic boundary 

 on the Blosseville Coast about 68° 30-69° N. Lat. This delimitation is 

 caused by the disappearance northwards of a flora connected with oceanic 

 climatic conditions and a similar diminution of true Arctic species in a 



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