ECOLOGICAL SIGNIFICANCE OF EAGLE CREEK FLORA 583 
Laurus 2, Platanus 2, Liquidambar 3, Crataegus 1, Sterculea 1, 
Rhus 1, Ilex 1, Acer 3, and Fraxinus t. 
Considering the ecological composition of the flora, the out- 
standing feature is the presence in it of leaves which represent two 
distinct ecological types, one xerophytic and the other mesophytic. 
The former includes several 
species of oaks, notably Quercus 
pseudo-lyrata (Fig. 2), which is 
the most abundant species in the 
flora. The latter comprises most 
of the remainder of the flora, in- 
cluding a large number of genera 
and species, of which Acer bendirez 
is represented by the largest num- 
ber of specimens. 
Quercus pseudo-lyrata, the 
most abundant species, is found 
in twelve of eighteen localities fur- 
nishing leaves. Clearly the con- 
ditions under which it lived may 
be said to be widespread. Its 
; Fic. 3.—Acer bendirezt. One-half 
leaves have the thickness and natural size. 
coarse epidermis which constitute 
the morphological expression of a xerophyte. Its modern repre- 
sentatives, Q. velutina, Q. muhlenbergit, and Q. marylandica, have 
their typical range in xerophytic habitats. It seems entirely 
probable that Q. pseudo-lyrata occupied a similar habitat, an 
exposed situation with a small amount of moisture. 
Associated with this presumably xerophytic species, commonly 
in the same slab and almost invariably in the same locality, is Acer 
bendirei (Fig. 3), a maple closely related to A. macrophyllum, which 
is an abundant member of the flora now living in the gorge. Even 
were it not well known that maples are almost exclusively found in 
well-watered habitats, the mesophytic character of Acer bendirei 
could be ascertained from the thin texture and large size of the 
fossil leaves. Occurring in fourteen out of eighteen localities it is 
an abundant species and one which shows moisture requirements 
widely different from those of Quercus pseudo-lyrata. 
