﻿198 Nichols: The vegetation of Connecticut 



humid regions like parts of eastern Canada the importance of 

 the mosses would hardly be overestimated. But, as indi- 

 cated by Transeau* and conclusively proved by Davis,t in 

 milder, less humid regions the mosses play at best a very subsid- 

 iary part in mat formation. In Michigan, according to these 

 authorities, the most important mat-forming plants are the sedges, 

 particularly Carex filiformis. This species is capable of spreading 

 rapidly by means of rhizomes. As pointed out by Davis, these 

 subterranean or subaquatic stems will often grow horizontally a 

 foot or more in length during a single season, producing at the 

 nodes an abundance of tough, slender roots, and bearing at their 

 tips terminal buds "from which new plants rise to send out in 

 ?s of horizontal stems. When conditions are un- 



favorable for the rhizomes to grow outward into open water, they 

 sometimes grow diagonally downward over the edge of the mat, 

 and thus the mat is strengthened as well as extended by the growth 

 of the plant." On account of its low specific gravity, the tangle 

 of roots and rhizomes thus produced floats on the surface of the 



* Bot. Gaz. 40: 363. 1906. 



