100 MIDLAND NATURALIST 
considerable interest. | Somewhat to the westward of the most con- 
spicuous group of Dakotan lakes, of which Devils’ Lake is largest, 
there exists a height of land, perhaps some fifty or a hundred miles 
in length, and possibly here and there almost as broad, which forms 
a natural barrier separating different water sheds. The trend of 
this very definite if not greatly elevated barrier is not quite meri- 
dional, but inclines to northwest and southeast, and from much be- 
low midway of it northward, the streamlets draining the elevation, 
if from the western slope flow to the Souris River, if from the 
eastern, to the Red River of the North; so that the major part of 
the whole drainage is, though by two separate and distinct main 
channels, tributary to Lake Winnipeg in the far North. 
rom the more southerly extension of the plateau the stream- 
lets draining it all flow to the Missouri, whether they arise from the 
eastward orthe westward slope of the elevation; and thus this 
southerly drainage has the Gulf of Mexico for its destination. 
Such, in rude outline, is one topographic feature of central 
North Dakota; and guided by the maps only, the student of plant- 
evolution and distribution would expect this to be something of a 
land of promise for peculiar and unusual forms and phases of plant 
life. It is a region where four different floras might be expected 
to meet and mingle. To the southward of it lies the western and 
more arid extension of the great prairies as these occupy eastern 
and middle Kansas and Nebraska. To the northward are the very 
different steppes of Manitoba and Assiniboia. Eastwardly lie the 
alternations of prairie and woodland that make northern Minnesota 
a region peculiar as it is vast. As closely adjacent on the western 
side of the plateau is that flora of the northern Rocky Mountains 
which occupies Montana. 
This, I say, is a peculiar district, where several extensive and 
well marked floras meet and mingle; or, putting the case different- 
ly, a kind of neutral ground whence radiate so considerable a num- 
ber of different phytographic regions. 
That this middle section of North Dakota really is such a phy- 
tograpically neutral ground has been impressed on my mind strongly 
by the examination of not a few botanical specimens that have been 
sent me from there for examination within the last five or six years. 
Whatever the family or the genus into which sendings fall, I have 
almost invariably found it difficult, and commonly quite impossible, 
to na y the species; this even in such familiar genera 
