4 UNIVERSITY OF MISSOURI STUDIES [146 



vision to correspond, the flora of the northern portion is much 

 poorer in species, hawthorn glades are more frequent, and the 

 vegetation in general is of a more lowland type than that of the 

 southern. The rupestrine flora is inconspicuous, while the ri- 

 parian is more noticeable. The swamp black oak (Quercus 

 palustris) which is almost absent from the region south, be- 

 comes common here. It is probable that formerly much of the 

 plains north were once prairie, though now the forest is in con- 

 trol. The prairies now begin between Columbia and Centra- 

 lia in the north of Boone county. 



Hinkson creek drains the region to the northeast, east, 

 south and southwest of Columbia. Roche Perche creek drains 

 the west and northwest. Of minor streams only Grindstone 

 creek and Bear creek need to be mentioned. The one drains 

 the region east and southeast and flows ultimately into Hink- 

 son creek; the other drains the country to the north. Hink- 

 son creek empties into Roche Perche creek just below Turner. 

 Brushwood lake is an abandoned channel of Roche Perche 

 creek. The Missouri, scarcely ten miles away to the southwest, 

 is the controlling factor in the physiography of the region. Its 

 cliffs and bottoms have, however, been only casually studied. 



1. The region north. — This may be described as a 

 plain slightly broken with ravines, through which small rills 

 ("branches"), or rather winter torrents, flow. These for the 

 greater part of the year are dry, though a few springs keep 

 portions of them moist. Bear creek introduces the chief elements 

 of unevenness in the surface. Its south bank lies close to a 

 wall of rock, which rises to a height of from forty to ninety feet. 

 Ponds of considerable size are frequent, though all, with per- 

 haps one or two exceptions, are of artificial origin. More's lake. 



