PREFACE 



Of all the botanical areas in the United States, 

 perhaps none has more sharply defined boundaries than 

 the Great Basin. Here we have a vast interior drainage 

 basin ; lofty mountains to the east and to the west, and 

 arid or semi-arid lands extending in nearly all 

 directions beyond its boundaries. Some few of the 

 plants of neighboring districts have succeeded in 

 passing these barriers, but have gotten no further; and 

 so here we find a meeting-place of the floras of the 

 east, of the west, of the north and of the south. And 

 yet this region never has had a botanical manual of 

 its own! Those who live on its western borders have 

 to be content with a Flora prepared for California; 

 while those on its eastern side must be satisfied with a 

 book taking the Continental Divide for its central 

 point, and extending westward to the Great Basin. 

 What wonder, then, that less than half of our species 

 are therein included, and that consequently the 

 teachers attempting systematic work find themselves 

 seriously handicapped! These small manuals have 

 been without exception unsatisfactory; as must be 

 every small book of this character which attempts to 

 cover a large area, especially where the area pretended 

 to be cohered consists of parts of several distinct 

 botanical areas. 9O1 O r>r 



