454 



Minnesota Plant Life. 



Several different classes exist, all of them characterized l)y the 

 development of the imderground portions of the plant— that 

 is. the roots or rootstock— in moist soil, while the aerial por- 



IM... -4-Marshy i.laceattheedneof a VV00.1. After photograph by Mur.lock. 



tions, especially the slarch-makino- areas, are exposed to atmos- 

 pheric evaporation. Like the majority of aciuatic plants, most 

 of the swani]) i)lants arc i)crcmiia 



ial. A sjrcal many of them 



