PU: Vegetation of the Dunes. 
How dunes are formed. 
Formed about certain grasses, and when large allow the 
development of trees and shrubs. 
Kinds of dunes. 
ieerotationary dunes, 
a. Embryonic. 
b. Mature. 
2. Wandering or active dunes. 
Dune formers require certain biological characters. 
I. Compact growth to check wind and precipitate sand. 
25 Perennial habit. 
3. Rhizome propagation. 
4. Ability of stems to grow out of’the sand when buried. 
-s. Highly developed xerophytic structures. 
6. Ability to stand root exposure. 
The best dune formers as found in the Lake Michigan region 
according to Cowles are as follows: 
1. Grasses with rhizome formation 
: Ammophila arundinacea. Most abundant. 
Agropyron dasystachyum. (northward). 
2. Grasses forming clumps. 
Elymus canadensis. 
Calamagrostis longifolia. 
25° olirabs. 
Salix adenophylia. Most abundant. 
Salix glaucophylla. 
Prunus pumila. 
Cornus stolonifera (or C. baileyi). 
Zee litees. 
Populus monolifera. 
Populus balsamifera. 
Size and age of dunes corresponds with their relation to the 
shore line. 
Size of the vegetation depends upon the location of the dune. 
Grasses, shrubs, open formations. 
Grasses, thickets, trees, older shrubs. 
Forests cover still older ones, which are continuous with 
forests on landward side. 
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