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IOWA ACADEMY OF SCIENCES. 
by three species {Ulmus Americana, U. racemosa and U. fulva). 
Only one, the slippery elm, is abundant on the loess formation, 
though Ulmus Americana is less restricted to low bottoms than 
U. racemosa. Of the maples the sugar maple {Acer saccliarinum) 
is common on the loess, while the soft maple {Acer dasycarpum) 
is exclusively a lowland species, so is box elder {Negundo- 
acer Okies). The mountain maple {Acer spicatum) occurs on the 
loess. Tilia Americana is common on the loess formation. 
Three cone bearing trees occur in northeastern Iowa {Abies 
balsamea, Pinus Strobus diiiadi Juniperus Virginiana), but they occur 
on other than loess soil. Of the ashes there are several species 
the Fraxinus viridis delights in low bottoms. The F. Americana 
occurs on higher soil. 
I cannot, in this connection, enumerate the shrubs that 
occur, but they are numerous and may occur in thickets in 
both loess and bottoms. Comparing the plants found in north- 
eastern Iowa with those about La Crosse, Wis. , where my 
early botanical work was done, I may say that most of the 
species occur and that the woody plants are more numerous. 
Some of the southern species, however, fail to appear, but in 
places northern forms occur. The density of the timber 
increases from the Mississippi east. In the drainage basin of the 
Kickapoo Valley the finest timber in western Wisconsin occurs. 
Nowhere have I seen such beautiful specimens of Acer saccha- 
rinum, Tilia Americana and Quercus macrocar pa. This, too, is 
outside of the loess region. In southwestern Minnesota, the 
statement of McGee that there is a significant relation between 
the loess sheeting and forest covering is very apparent. 
The most significant fact appearing to one who has made a 
study of the loess flora of western Iowa is the absence of trees, 
except an occasional cottonwood, cn the peculiar mounds that 
occur in parallel ridges along the Missouri river. These 
peculiar hills rise abruptly from the rich, fertile Missouri bot- 
tom and somewhat resemble the low foot hills of the Rocky 
mountains. They are from 100 to 200 feet high. Prom a dis- 
tance they look bare, but a day spent in this region will show 
that the hills are full of botanical interest. I have made four 
botanical trips at different tim.es along the Missouri. On the 
whole there is very little variation in the flora of Iowa. If we 
leave out of consideration a number of most interesting plants 
found in Winneshiek county by Mr. Holway and a few peculiar 
southern plants found by Mr. Perd Reppert, near the city of 
