158 AMERICAN MIDLAND NATURALIST. 
man has not interfered, it has a beautiful growth of Quercus 
macrocarpa, Populus balsamifera candicans, deltoides and 
tremuloides, Betula papyrifera, Acer fraxinifolium, Fraxinus 
lanceolata, Ulmu us fulva, Prunus pennsylvanica, etc. and plants 
like Unifolium canadense, Limnorchis hyperborea, Serentopis 
roseus, Doellingeria umbetlata pubens, Aster Saundersii, Rud- 
beckia ampla, Erigeron lonchophyllus, etc., showing its ten- 
dency for making selections from different floras. The Souris 
enters the state from Canada, runs south, makes a bend, and 
returns to Canada. This bend has a length of about 75 miles 
and a width of te ase In Canada it joins the Saskatsjavan 
- River on its way to Lake Winnipeg, the same lake being the 
outlet for the Red jum of the North, before all these waters 
jointly make a final dash for Hudson Bay. The flora of the 
Souris basin and adjoining prairies north and south of the 
Canadian boundary shows a striking similarity. In the early 
September anno 1902 I made an excursion to Assiniboia, 175 
miles north of the boundary line, anticipating a rich harvest 
of Canadian fall plants. Along the track were growing ev- 
erywhere Helenium montanum, a common North Dakota 
plant, and a beautiful Coreopsis, which I expected to collect 
when the train stopped at some station. But the Canadian 
stations were just like all other stations. Chenopodium al- 
bum, Sinapsis arvensis, Bursa Bursa-pastoris and other fa- 
miliar plants were the only floral representatives there. All 
native plants shun the stations. I failed to collect that 
Coreopsis. I left the train at Moose Jaw, searched the prairie, 
the waste places, the gravel pits and the thickets along the 
Saskatsjavan River, and but for one Rosa species and one va- 
riety of sae laevis I found only old North Dakota acquaint- 
ances. On the other hand, one plant, accredited as exclusive- 
ly Canadian, A ido dr s Sisyrhinchium septentrionale, grows a 
few rods from my residence lot at Leeds, North Dakota. 
I have a limited knowledge of the flora west of the great 
divide. On May 2, 1903, I made an excursion lasting one 
hour, while I was waiting for e fast express train at Willis- 
i : collected five species belonging to the Montana flora. 
the Coteau you will at this early season find only the 
cnni => the leaves) of Pulsatilla Ludovician 
woodland flora of the east is dtm ‘best ros 
sented i. protected localities where trees can grow. 
entering such a wooded piece of land, you find that the shaken 
from the prairie flora is instantaneous. Very few plants adapt 
themselves to both i res pera Such a plant is Steironema 
ciliatum, which has a very rank and luxurious growth in the 
thicket, but dde down to half its ordinary size on the 
prairie. Another such plant is Galium boreale, which reaches 
