1 64 



Minnesota Plant Life. 



by all who frequent the woods. Of true ferns there are nine 

 families, only four of which are represented in Minnesota. 

 The filmy ferns, the tree-ferns, the forking ferns, the twining 

 ferns and the Borneo ferns are not represented by plants in- 

 digenous to the state. The families present are the bracken- 

 ferns and their various allies, the flowering ferns, the floating- 

 ferns and the four-leaved water- 

 ferns. Of these the lowest in type 

 are the flowering ferns, three spe- 

 cies of which occur in Minnesota. 

 One of them, known as the inter- 

 rupted fern, is a common plant, 

 presenting a peculiar appearance as 

 if somewhere near the middle of the 

 large leaf two or three leaflets had 

 shriveled. These leaflets, unlike 



Fie*. 54. A quillwort plant. After At- 

 kinson. 



FIG. 55. Clayton's or interrupted fern. After 

 Hritton and Brown. 



the rest, have a brown and withered look. If examined closely 

 it will be discovered that this is due to their being covered with 

 spore-cases of a brown color, while the rest of the leaflets pro- 

 duce no spore-cases whatever. Another fern of this family is 

 the cinnamon fern which forms leaves of two sorts, some 



