THE ROLE OF SEDGES IN SOME COLORADO PLANT 
COMMUNITIES 
Francis Ramaley 
Every botanist is well aware of the large part taken by sedges in the 
vegetation of lake shores and swampy areas. For the eastern United States 
the species involved are well known, as also their relative importance in 
different stages of succession. Sedges of lake shores in the Rocky Moun- 
tains have been referred to by Clements (i), Ramaley and Robbins (7), 
Ramaley (4) , and Robbins' (9) • In. the present paper additional facts are given 
as to sedges of pondsides together with a series of observations on sedges of 
mesophytic and xerophytic habitats. This paper is based upon studies 
carried on largely from the University of Colorado Mountain Laboratory 
at Tolland, Colorado. Statements in the paper apply chiefly to the north- 
ern part of the state and to the mountain districts rather than to the plains. 
All species mentioned are well-known constituents of the Colorado flora. 
The nomenclature employed is that of Rydberg's "Flora of the Rocky 
Mountains and the Adjacent Plains" (New York, 1917). The various life 
zones are given the following names in accordance with customary usage: 
Plains, Foothill, Montane, Subalpine, Alpine (4). 
Sedges exist chiefly in primitive communities or unstable situations. An 
area in a region that is climatically mesophytic becomes eventually either 
forest or grassland in which sedges have a very small place. So also, a 
climatically xerophytic area grows poor in sedges as the ultimate type of 
vegetation appears. Most sedges are aquatics or marsh plants or else they 
are xerophytes. Only a few are true mesophytes, and even these are likely 
to become crowded out by grasses and herbaceous dicotyledons in a meadow 
which has developed from marsh. Meadow or prairie of xerarch origin is 
also typically without sedges, the xerophytic sedges of more primitive stages 
disappearing before the meadow stage is reached. In the following system- 
atic account the various genera of Cyperaceae are briefly considered, but 
chief attention is given to Carex. 
SCIRPUS 
Scirpus lacMstris and other species of the genus are too well known every- 
where to need description or comment. At lower elevations in Colorado, 
i. e., on the plains, they behave very much as in the eastern part of the United 
States. They are found to some extent in the foothill area but are typically 
absent from lakes of the montane and higher zones. 
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