(is 



Plate 21.— Classification: system Riverine, SUBSYSTEM Lower Perennial, CLASS Emergent Wetland, SUBCLASS Nonpersistent, 

 water regime Semipermanently Flooded, water CHEMISTRY Fresh-Circumneutral, SOIL Mineral. Dominant plants are 

 arrow arum (Peltandra virginica) and pickerelweed (Pontederia cordata). (Hampden County, Massachusetts; July 1970) 



