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7 



THE VEGETATION OF THE HACKENSACK marsh: A TYPICAL AMERICAN FEN 



the peaty tracts of eastern England, which are characterized by alkaline 

 waters, are spoken of usually by the local inhabitants as "black fens," or 

 simply fens characterized by alkaline waters and by a high, soluble mineral 

 content — especially by a high lime content. Accordingly, the vegetation of 

 acidic peat may be said to belong to the moor formation, and that of the 

 alkaline peat (muck) to the fen formation. The lists of plants for the two 

 formations bring out in a marked degree these fundamental differences. 



The aquatic and marsh vegetation of Esthwaite Water has been investi- 

 gated recently by W. H. Pearsall,* who shows that the conditions of sedimen- 

 tation influence the character of the associations. The reed swamps of the 

 area of rapid sedimentation are peculiar in the absence of Scirpus lacustris, 

 the presence of Typha latifolia, and the abundance of herbaceous species. He 

 describes the mixed fen associes, which succeed reed swamp, as also the vege- 

 tation of the areas of moderate and slow sedimentation. 



FENS OF SWITZERLAND 

 For Switzerland, Friih and Schroter, in a monumental contribution, 

 describe the flachmoor (reed marshes) of that country. They recognize a 

 number of different types which owe their character to the plants which are 

 associated. The roseau (Fr.), cannetta (Ital.), reed (Engl.), is the tallest and 

 most abundant constituent of the fens of Switzerland. Its rhizomes spread 

 horizontally considerable distances, forming a mat which binds the mud and 

 slimy ooze into a rather firm mass. It contributes largely to the formation of 

 the muck. The nodes of the creeping stem give rise to upright halms and 

 roots. In such Swiss lakes as Lake Zug, there are scattered areas of Phrag- 

 mites communis along the lake shores. Here it is associated with Scirpus 

 lacustris, which is codominant with it. The width of the areas where these 

 two plants are found depends on the depth of the water, which is shallow, 

 especially along the west shores of the lake. 



PAPYRUS MARSHES IN SICILY 

 Near Syracuse in Sicily are two small rivers, the Anapo and the Ciani, 

 which are characterized by growths of the papyrus {Cyperus Papyrus), the 

 physiognomy of which resembles that of the fenlands of England and else- 

 where, and in the broad sense the papyrus marsh may be included in the fen- 



* Pearsall, W. H.: Jour, of Ecol., VI: 75-83, March, 190S. 



