POBEST MISTKMIM'TIOX 



ndudinir not only the amount of seed and 

 : years, Imt tin- comparative a^es at which 



seeds are produced, their viability, their mode of dissemination 



and germination and the time involved, the requisite conditions 



-t'nl pollination, etc. In addition to these factors must 



iDsidered the matters of specific protoplasmic functions. 

 such as resistance, or siiscept ihilit y. to the attacks of destnict ive 



-. in- fumri. the ran. ir- of adaptability in relation to climate 

 and soil. Only by an appreciation of the value of these and 

 other factors an the relative importance of a species in any 

 irivi-M area be fully understood. Furthermore, it would seem 

 that no estimate of the influence of these causes is adequate 

 which does not take some account of the time during which the 

 various influential factors have been operative. 



The immensity of the task involved in the thorough study 

 of th" vegetation of an area becomes the more apparent when 

 we reflcrt that native vegetation is dynamic, not static, and 



he rhanirinir Duality of the soil thnmirh lonir periods of 

 time is attended by conspicuous ch an ires in the plant coverinir. 



Our knowl-d'jc ,,f tl colony of a region or locality must in the 



end be a product of our knowledge of the separate units (species) 

 of that area. It seems, therefore, important that the study of 

 plant ireoirraphy. or ecology, be approached primarily from the 

 standpoint of the species and merely incidentally from that of 

 the physical conditions. 



It is the ;iim of this paper ! present an introduction to the 



Niihjr est distribution in a portion of the northern Rocky 



Mountains, with a few tentative conclusions, and to point the 



to a more t horoii-_;h study, the results of which should be 



of ifn: . both in their scientific and their economic as- 



th- present time, the flora of Montana has been 



rom the .standpoint of the systematist. More 



than a century of botanical i-xploration. from the time of Lewis 

 and Clark to the present day. has made known to us the prin- 

 cipal OOmpOn tl N'T;, The first collection within the 

 N\as th.i- ..!' Iferiwether L-'\\is m IMH|. who traversed the 

 of the ,1,1 Lo| 1( |';iss in the Hitter Root 

 Range throu'jh the l|e||'_Mte ;md I ', | ;i ,- 1< f < -ot eniuitrv via 



