130 B Canadian Arctic Expedition, 191Srl8 



There are also many types of inflorescences represented in these regions 

 but the umbel is rare; and with regard to the floral structure, the actinomorphic 

 and zygomorphic ones are both common and almost equally represented.. 

 With regard to the fruit, the_ fleshy type is rare and does not seem to mature 

 every year as is evidenced 'in the genera Vaccinium, Empetrum, .Rubus, and 

 Arctostaphylos. 



Certain biological types of plants are totally absent from the polar regions ; 

 there are no climbers and no true parasites of the Cuscuta or. Arceuthobium type; 

 yet Pedicularis is a root-parasite but one having a green foliage; saprophytes 

 seem to be absent altogether. 



Thus, with but a very few exceptions, viz.: Pedicularis, the arctic flora is 

 composed of autophytes, herbs as well as shrubs, with the great majority of 

 the herbs perennial, Koenigia, Gentiana, and Pleurogyne being the only annuals 

 in arctic North America, not including a few accidentally introduced weeds. 



Considering the general characteristics of the arctic plants, one cannot 

 help but recall the picture of the alpine flora in general. Practically, the arctic 

 flora is diversified to the same extent and represented by the same elements; 

 the families, genera, and species are either identically the same or represented 

 by analogous types, some of which may be endemic while others may have 

 immigrated from other districts. This similarity in composition existing between 

 the arctic and the alpine floras, as well as the analogy in the morphological 

 structure of the plants, is, nevertheless, associated with such diversities of 

 conditions as offer, for instance, the tundras of the arctic and the alpine summits 

 of the south. 



Concerning the origin of the arctic and of the alpine vegetation as it 

 now exists, it may be mentioned that Nathorst is in favour of the supposition 

 that the arctic vegetation, at least to some extent, originated in the lowlands of 

 the polar regions, but that the greater portion was originally alpine. To draw 

 the line between these two elements seems impossible, even if we may feel 

 entitled to consider most of the circumpolar species to have originated in the 

 north; and besides, there are quite a few species which are not circumpolar but, 

 nevertheless, better represented in the north where they are more abundant; 

 these may also be considered remnants of an arctic vegetation. 



With the morphological structure so remarkably uniform in the arctic 

 and alpine elements, we must consider them from another viewpoint, namely 

 as "species." Developed as such, the arctic element appears, sometimes, as 

 more or less isolated types like Pleuropogon, Dupontia, Arctophila, Tofieldia, 

 Oxyria, Koenigia, Monolepis, Merckia, Douglasia, Pachypleurum, etc. Or we 

 may trace an arctic origin in species of even large genera, \^hether circumpolar 

 or simply arctic. For instance, Saxifraga contains types some of which are de- 

 cidedly of arctic, others of alpine origin, as demonstrated in the preceding pages. 

 Ranunculus, Stellaria, Potentilla, and several other genera, not speaking of the 

 Gramineae and Cyperaceae, also illustrate such diversity of origin, arctic or 

 alpine. 



As a matter of fact, several of the genera characteristic of the polar regions 

 are monotypic or nearly so; or in case of large genera, the arctic species are not 

 infrequently somewhat isolated, i.e. from a systematic point of view, as if actually 

 representing glacial types of the respective genera. I think especially of Cam- 

 panula unifiora. Polygonum viviparum, Eutrema Edwardsii, Braya purpurascens. 

 Parry a macrocarpa, P. arctica, Ranunculus glacialis, R. Pallasii, Saxifraga 

 flageUaris, Salix polaris, S. reticulata, etc. And judging from their present 

 geographical distribution I take these to be arctic types having originated in 

 these regions and acquired a specific structure which makes them distinct from 

 such of their congeners as are also distributed in the arctic regions but of which 

 the original centre, appears to have been located farther south, and principallj^ 

 in the higher mountains. 



