148 
Ohio Biological Survey 
this flood plain, and leaving it as a terrace. The bed of the stream is 
limestone. Beech is still dominant on the ravine slopes, and extends down 
nearly to the stream (fig. 20 ). But other trees are beginning to appear, 
sugar maple (Acer saccharum) first, and later, wild black cherry (Primus 
serotina), tulip tree (Liriodendron Tidipifera), sweet buckeye (Aesculus 
octaiidra), and sometimes white oak (Qucrcus alba) and red oak (Quercus 
rubra). Occasionally sugar maple or tulip almost entirely takes the place 
of beech. If the dominant tree is tulip, the lower zones of the forest are 
well developed, because tulip admits a greater amount of light than either 
Fig. 21. The tulip tree (Liriodendron Tnlipifera) is the facies in this woods. 
beech or sugar maple (fig. 21 ). This is a mesophytic forest, very differ¬ 
ent in appearance from the mesophytic forest of the upland. The under¬ 
growth is more varied and denser, being made up of a large variety of 
saplings, among which beech and maple are most numerous; dogwood 
(Cornus dorida) and papaw (Asimina triloba) are abundant. Instead of 
the scant herbaceous vegetation of the upland beech woods, a varied 
spring flora is found in which Claytonia virginica (spring beauty), Phlox 
divaricata, Hydrophyllum appendiculatum, Trillium erectum, Dentaria 
laciniata (toothwort), and violets (Viola papilionacea, V. canadensis, V. 
striata, and V. pubescens) are perhaps the most characteristic plants. 
