SKETCH OF THE FLORA OF ALASKA. 



441 



The area of Alaska, as computed by the United States Coast Survey, is 570,000 

 square miles, including' tlic islands. Chester county, of the State of Pennsylvania, 

 has but 738 square miles, yet it has just aljout double the number of indigenous 

 flowering plants that Alaska has. This, however, only implies poverty of 

 specific forms and not necessarily of flora ; for we find Alaska covered during 

 its short summer with a luxuriant growth of vegetation, but not of so diversified 

 a character as that of more favored regions. 



The proportion of ferns is quite hirge in ALaska. This is accounted for, doubt- 

 less, by the saturated condition of the atmosphere, combined with the deep shade 

 of its more southern forests. 



I would here gratefully acknowledge the assistance I have received in pre- 

 paring this jiaper from Professor Gray and Dr. George Thurber. To Messrs. 

 James and Mann my thanks are also due ; their names appear over their respective 

 communications. Messrs. Bannister, Dall, and Bischott" have each added to the 

 plants hitherto known from Norton sound, Sitka, and the Youkon River district. 



I have depended chiefly on the following works: Flora of North America, 

 vols. 1 and 2, Torrey and Gray ,• Hooker's Flora Boreali Americana ; Ledebour's 

 Flora Rossica; Bongard's Vegetation of Sitka; Hooker and Arnott's Botany of 

 Beechey's Voyage ; Seemann's Report on the Botany of the Voyage of the Her- 

 ald ; J. D. Hooker on the Distribution of Arctic Plants ; and Dr. Ly all's Report 

 on the Botany of Northwestern North America. In the main I have adopted 

 the order of arrangement and the nomenclature of the Flora Rossica. When 

 the complete flora of Alaska is to be published it will be early enough to cease 

 following a guide so satisfactory as Ledebour is, on the whole. However, when 

 a manifest improvement has been suggested by later authorities I have not hesi- 

 tated to adopt it. 



It is hardly necessary to remark that, in-espective of further discoveries, the 

 varied views of different authorities as to what constitutes a species, might sen- 

 siltly affect the absolute number recorded in this list. So far as the plan upon 

 which it is formed aftbrded the opportunity, I have adopted the wider view of 

 species as best according with modern philosophic botanical teaching, and as 

 by far the least likely to involve absolute error. 



The field which is here merely outlined will offer a rich harvest to the botanist 

 who can devote to the subject the time it demands for thoroughly scientific treat- 

 ment. The proximity of the two continents and their islands would lead us to 

 think Alaska might prove a good ground for clearing up some doubtful points 



