10 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



differences, similar characters must be given equal consideration in 

 all families. 



The Pacific northwest is a region with great physiographic and 

 correspondingly gi*eat climatic differences. In consonance with the 

 physical factors there are many and striking ^peculiarities in the dis- 

 tribution of the plant species occupying this area, and the attempt is 

 here made on the basis of the writer's familiarity with the region, 

 and the recorded data of others, to determine some of the complex 

 causes which have brought about the present plant distribution. 



It is more than possible that some of the conclusions here reached 

 or suggested may be based quite as much on our lack of knowledge 

 as on definite information. AVhile this may eventually prove to be 

 the case, the suggestions here advanced nuiy nevertheless serve as 

 working hypotheses when a more complete l)otanical survey shall be 

 undertaken. 



Many of the data upon which the origin of the present flora of 

 Washington depends must he sought to the southward, a region here 

 considered only incidentally, but which nnist needs be more fully 

 explored before certain conclusions here suggested can be either veri- 

 fied or overthrown. 



THE BOTANICAL EXPLORERS OF WASHINGTON. 



The following brief account of the botanical explorers of Wash- 

 ington refers to their labors mainly in so far as they concern the 

 region covered by this work. Inasmuch as both Washington and 

 Idaho were included in Oregon until 1858, many of the earlier col- 

 lections in these States are ascribed simply to " Oregon," though 

 Washington and north Idaho are sometimes referred to as " Upper 

 Oregon," notably in Geyer's explorations. Before the name Oregon 

 became attached to the northwest Pacific region the interior portions, 

 especially south Idaho and eastern Oregon, were more or less vaguely 

 included in " Upper California," a phrase not unusual on Douglas's 

 plant labels, and quite frequentlj^ used in the Botany of Beechey's 

 Voyage. Still earlier than this the name " New Georgia " wan em- 

 ployed, mainly for the region bordering Puget Sound and the Ciulf of 

 Georgia. The most vague term of all, " Northwest Coast," has been 

 made by different writers to include everything from the northern 

 boundary of California to Prince William Sound, Alaska, and the 

 approximate meaning of this phrase can be gleaned in each case 

 where used only by indirect means. 



The botanical explorations of Washington are conveniently grouped 

 into two periods. The first of these includes all the explorers previous 

 10 1860, namely, Menzies, Lewis, Douglas, Scouler, Tolmie, Gairdner, 

 Wyeth, Nuttall, Pickering and Brackenridge, Geyer, Spalding, Jef- 



