242 NICHOLS: THE VEGETATION OF CONNECTICUT 
The Mesophytism of the Flora in Rock Ravines.—A rock ravine, 
more than any other sort of habitat, affords environmental condi- 
tions congenial to pronounced mesophytic plants. Seepage water 
is usually abundant along the sides, there is protection from sun 
and wind, and the humidity of the air, as compared with the 
surrounding upland, is high. Certain mosses and liverworts are 
practically confined to such habitats. In a more arid region than 
Connecticut the same observation might be made with regard 
to many of the higher plants, but while it is a familiar fact that 
in this region as elsewhere the flora of rock ravines includes many 
of the most extreme shade- and moisture-loving ferns and flowering 
plants, most of the species present are equally representative of 
other habitats. Species intolerant of shade are largely excluded. 
The majority of the forms cited in earlier papers as typical of 
the climax forest of this region are to be found here, and not a few 
of the common plants of rock ravines thrive elsewhere in wooded 
swamps. The following list includes a number of ferns and 
herbaceous flowering plants which may be considered character- 
istic of rock ravines, though by no means peculiar to them. 
Polypodium vulgare 
Phegopteris polypodioides 
Asplenium Trichomanes 
Asplenium acrostichoides 
Aspidium spinulosum 
Cystopteris bulbifera 
Cystopteris fragilis 
Lycopodium lucidulum 
Arisaema triphyllum 
Smilacina racemosa 
Streptopus roseus 
Trillium erectum 
Laportea canadensis 
Pilea pumila 
Solidago latifolia 
Asarum canadense 
Actaea rubra 
Caulophyllum thalictroides 
Chrysosplenium americanum 
Impatiens pallida 
Viola cucullata 
Viola blanda 
Viola rotundifolia 
Circaea alpina 
Aralia racemosa 
Sanicula gregaria - 
Hydrocotyle americana 
Cryptotaenia canadensis 
Collinsonia canadensis 
The Ravine Forest.—The intense mesophytism of a rock ravine 
is further accentuated by the nature of the ravine forest (FIG. 3). 
As a rule the hemlock and yellow birch are prominent, and more 
often than not they predominate. Along with them commonly 
