Arctic Plants: Geographical Distribution 81 b 



alpinum, Papaver, nudicaule, Draba fladnizensis, Cardamine pratensis, Saxifraga 

 cernua, S. Hirculus, S. nivalis, S. hieradifolia, S. decipiens, S. oppositifolia, 

 Sedum Rhodiola, Dryas, Potentilla nivea, P. palustris, Empetrum, Epilohium, 

 Erigeron uniflorus, and E. alpinus. 



From this small enumeration it will be seen that most of these species may 

 have their spores, seeds, or fruit readily dispersed by means of the wind, especially 

 the Pteridophyta, the Gramineae, Cyperaceae, notably Eriophorum, the Salix, 

 Oxyria, Dryas, etc. But Saxifraga cernua, Polygonum viviparum, and perhaps 

 also Cardamine pratensis form an exception, since the production of bulblets has 

 taken the place of fertile flowers; with regard to Empetrum, the seeds of the 

 fleshy fruits may be dispersed only by means of animals. 



However, many of the other species are just as well adapted to be dispersed, 

 especially by the wind; thus their more or less scant distribution farther south 

 may be due to their local extermination, or perhaps because they may represent 

 young species of northern origin. I think especially of the willows, which un- 

 doubtedly have an important centre in the northern regions. 



With regard to the truly arctic element, there are several species which, 

 although not being circumpolar, may be looked upon as genuine arctic types, 

 and some of these have not, so far, become distributed farther south. Among 

 these may be mentioned Hierochloe pauciflora, Poa abbreviata, Glyceria, Carex 

 stans, C. subspathacea, C. reducta, C. compacta, Luzula nivalis, Salix rotundifolia, 

 and several other species of Salix, Rumex, Lychnis Taylorae, Alsine macrocarpa, 

 Merckia, Anemone Richardsonii, Ranunculus Pallasii, R. Sabinii, Lesquerella, 

 Cochlearia, Draba corymbosa, Braya purpurascens, Hesperis, Cardamine digitata, 

 Parrya arctica, Saxifraga radiata, Dryas integrifolia, Sieversia, Potentilla pul- 

 chella and several other Potentilla species, Rosa adcularis, Lupinus, Hedysarum, 

 Selinum, Pyrola, Cassiope, Dodecatheon, Primula borealis, P. stricta, Gentiana, 

 Phlox, Mertensia Drummondii, Pedicularis hirsuta, P. arctica, P. capitata, Lagotis, 

 Aster, Achillea, Chrysanthemum integvifolium, Artemisia vulgaris var. Tilesii, 

 Arnica, Senecio resedifolius, Saussurea, Taraxacum, and Crepis. About 60 

 species, and adding to these the 80 circumpolar ones, we have in all 140 species, 

 collected by the expedition, which may be termed strictly arctic, so far as we 

 know, at least in accordance with their present distribution, being absent from 

 regions farther south. The remaining species, about 90, may be partly such as 

 have originated in the arctic regions, but of which a certain element remained 

 in the mountains, while the others returned. And another part consists of 

 southern species, which accompanied the arctic on their retreat. These southern 

 species cannot with certainty be defined, except that their distribution in the 

 arctic region, being either very scant or scattered, might indicate their southern 

 origin. As far as concerns the structure of arctic species, it has been shown in the 

 preceding pages that no morphological structure seems absolutely characteris- 

 tic of these; they share the same development of their floral and vegetative 

 organs with their southern, aUied species; they exhibit exactly the same method 

 of vegetative reproduction as these, and are, indeed, in many cases not of such 

 dwarfed stature as frequently described. But they resemble alpine plants, 

 and they are, with but very few exceptions, perennial Kke them. 



There is thus no absolute morphological character by which arctic and 

 alpine species may be defined, and we must therefore consider them from other 

 points of view, when the question arises to distinguish them, in the present case 

 to draw the line between the northern and southern element. It may be possible 

 to establish such a distinction by means of comparing the genera, or in some 

 cases the species. And in this case we are allowed to include, but only as supple- 

 mentary, peculiarities in their morphological structure. 



In the subsequent pages I shall endeavour to show the importance of the 

 present geographical distribution in defining the probable location of the 



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