Ecology of the Cincinnati Region 
171 
3. Gravel bluffs 
The Little Miami and Miami rivers are, in many places, cutting bluffs 
in the gravels with which these valleys were partly filled during the 
Wisconsin glacial epoch. The gravel bluffs vary from forty to seventy 
feet in height. The under-cut banks stand at high angles, owing to a 
partial cementation of the gravel at some horizons. 
The new bluffs are devoid of vegetation, except that brought down 
from the top by slides, as the loose gravel is constantly slipping (fig. ^y). 
At the top of the bluffs, and in those parts where erosion is not very 
active, a few xerophytic herbs appear, among which are Verbena stricta, 
Kiihnia eupatorioides, Arabis Drummondi, and Poa conipressa. These 
are all sun plants, and persist but a short time in the life of the succes¬ 
sion. 
Fig. 37, Gravel bluff of the Little Miami river near Milford. 
Toward the upper end of the under-cut bluff, a few xerophytic trees 
and shrubs are seen advancing upon the open herbaceous association 
37)- Foremost among these are red elm, chestnut oak, blue ash, 
hop hornbeam, red cedar, and Rhus canadensis. 
