DR. HOOKER ON THE DISTRIBUTION OF ARCTIC PLANTS. 



269 



Populus tremuloides. Spiranthes gracilis. Carex oligosperma. 



Picea nigra. Cypripedium acaule. Pleuropogon Sabini, 



Of these Douglasia and Fleuropogon are the only ones absolutely peculiar to Arctic 

 East America. It is a noticeable fact that not one of them is found in any part of Green- 

 land. Compared with Greenland, the Arctic East American flora is rich; =containing, 

 besides those just enumerated, no less than 165 other species not found in Greenland. 

 The following are found on the arctic islands, and many of them on the west coast of 

 Baffin's Bay, but not in West Greenland :— 



Caltha palustris. 

 Parry a arctica. 

 Merkia physodes. 

 Stellaria crassifolia. 

 Astragalus alpinus. 

 Oxytropis campestris. 



Uralensis. 



nigi-escens. 



Sieversia Rossii. 

 Saxifraga hieracifolia. 



Virginiensis. 



Hirculus (East Greenland 



only). 

 Valeriana capitata. 

 Nardosmia corymbosa. 



Ptarmica vulgaris. 

 Chrysanthemum arcticum. 

 Artemisia vulgaris. 

 Senecio frigidus. 



palustris. 



pulchellus. 



Solidago Virga-aurea. 

 Aster salsuginosus. 

 Crepis nana. 

 Saussurea alpina. 

 Andromeda polifolia. 

 Arctostaphylos alpina. 

 Kalmia glauca. 

 Phlox Sibirica. 



Pedicularis capitata. 



versicolor. 



Androsace septentrionalis. 



Chamsejasme. 



Salix phlebophylla. 

 Lloydia serotina. 

 Hierochloe pauciflora. 

 Deschampsia csespitosa (East 



Greenland only). 

 Glyceria fluitans. 

 Pleuropogon Sabini. 

 Bromus purgans. 

 Elyraus mollis. 



Castilleja pallida. 



There are thus no fewer than 184 of the 379 Arctic East American species (fully 

 half) which are absent in West Greenland, whilst only 105 (much less than one-third) 

 are absent in Europe. This alone would make the limitation of species in the mei'idian 

 of Baffin's Bay more decided than in any other arctic longitude ; and I shall show that 

 it is rendered still more decisive by the number of Arctic Greenland plants that do not 

 cross to Arctic East America. 



Of the 379 Arctic East American species only 56 are not found in Temperate East 

 America, of which two are absolutely confined to this area ; two others {Farrya arenicola 

 and Festuca Richardsoni) to Arctic East and West America ; 25 are found in Temperate 

 West America, and about 20 are Rocky Mountain species, and not found elsewhere in 

 Temperate America. 



Eor our knowledge of this flora I am principally indebted to the ' Elora Boreali- Ameri- 

 cana,' and to Richardson's* botanical appendix to Franklin's first voyage — and his 'Boat 

 Journey through Rupert's Land.' I have also examined the materials upon Avhich the above 

 works were founded, and the collections of almost every subsequent journey and voyage, 

 up to those of Dr. Walker in the ' Eox.' To enumerate the numerous botanical appendices 

 to voyages, and separate opuscules to which these have given rise, from Ross' first voyage 

 to the present time, would be out of place here. I have endeavoured to embody in the 



* I am indebted to Sir John Richardson for some corrections to this list, which account for a few discrepancies be- 

 tween his lists of Arctic American plants and my own ; these refer chiefly to genera and species introduced into his 

 lists, but liere excluded. 



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