Nichols: The vegetation of Connecticut 253 



Asarum canadense Hepatica triloba 



Claytonia virginica Anemone quinquejolia 



Thalictrum dioicum Caidophyllum thalictroides 



Anemonella thalictroides Sanguinaria canadensis 



Smilacina racemosa Dicentra cucullaria 



Polygonatiim bifiorum Dentaria diphylla 



Medeola virginiana Dentaria laciniata 



Trillium erectum Viola pnbescens 



The Vegetation of Rock Bluffs.— In comparing rock bluffs with 

 rock ravines, one striking dissimilarity concerns the bryophytic 

 flora. Species inhabiting the rock-face or the crevices, together 

 with certain of the forest-floor species, may be well represented, 

 but most of the others are absent. Under favorable circumstances 

 a rock bluft' may support a highly mesophytic vegetation; much 

 apparently depends on exposure and on ground-water relations. 

 Along the Connecticut River, south of Middletown, the north- 

 facing blufi^s are (or were) well forested; most of the vascular 

 plants already cited as characteristic of rock ravines grow luxuri- 

 antly; Acer pennsylvanicum is common, attaining a height of 

 more than thirty feet; and the mesophytic ravine mosses are well 

 represented. The vegetation on the south-facing bluffs across 

 the river, however, especially as regards the herbaceous flora, is 

 much less mesophytic. In general, north- or east-facing bluffs 

 are more mesophytic than those which face south or west. As 

 might be expected, the highest degree of mesophytism prevails 

 toward the bottom of a bluff; toward the top the vegetation is 

 more xerophytic. In some cases, where the water supply is 

 insufficient, mesophytes may be virtually lacking and xerophytes 

 predominate from top to bottom. On the whole, the vegetation 

 of the rock bluffs which border stream valleys throughout the 

 state resembles that which has been described elsewhere* as 

 characteristic of talus slopes. 



Flood Plains 

 The topographic changes which take place during the building 

 up of a flood-plain are accompanied by a fairly definite succession 

 of plant associations. In the earlier stage s of flood plain develop- 



* See Torreya 14: 181-184. 1914. 



