122 MISSOURI BOTANICAL GARDEN. 
upward to the top of them, and a well defined trail leads 
from the top of one mound down the side and along the 
low backbone to the side and top of the next mound, and 
so on to all the mounds. 
I have found these trails of considerable advantage in 
climbing over and around the mounds, and in going from 
one mound to another, and I have never seen one isolated 
mound in Atchison County. 
The south and west sides are those which are steep and 
precipitous, but sometimes they descend gradually to the 
bottom lands at their bases. The north and east sides are 
usually descending and are covered with a short thick 
growth of trees and shrubs near their bases, but which does 
not rise as high up on the north side as on the east, as it 
sometimes reaches quite to the top on the latter. 
The texture of the soil is a thin, slightly sandy loess, 
very compact and hard, so much so, that names carved in 
the face of the steep sides endure for many years. The 
fertility of the soil is very low and supports only such plants 
as will thrive in similar conditions, being covered with a 
short growth of grasses, such as Bouteloua hirsuta, B. oli- 
gostachya and Sporobolus airoides. 
There is a belt of heavy timber back of the mounds, 
which averages about one mile in width, and which is some- 
what lower than the mounds, and back of this is a high 
rolling prairie, which is considerably lower than the mounds. 
Between the mounds and the Missouri River is an extremely 
fertile gombo bottom-prairie which is sometimes several 
miles in width, and often not a mile wide, which has a flora 
very similar to the general Missouri River bottom flora, 
except that a few of the peculiar species of the mounds are 
here present and should not be considered as characteristic 
of it. 
Where the south and west sides are steep and precipitous, 
there are to be found in abundance such plants as Yucca 
glauca, Gaura coccinea, Psoralea argophylla, Meriola ser- 
rulata and Sporobolus airoides; where they descend gradu- 
