PERNS 



415 



76. Ferns (FUicales) . — The Filicaks are composed of 

 the true ferns and the water ferns. Water ferns are small 

 aquatics, sometimes introduced into artificial ponds. They 

 are of sHght importance as compared with the true ferns. 

 Of all pteridophytes the true ferns are, to you, by far the 



Fig. 206 a. — The fossil of an ancient fern. 



most important group. They are by far the most abun- 

 dant and familiar. They are handsome plants. You have 

 admired their large, graceful, much-divided leaves. Per- 

 haps you have seen them growing abundantly in moist 

 woods and have brought them home to plant. (See 

 Figure 20^.) In conservatories you may have seen the 

 beautiful tree-ferns of the tropics. Though they are 

 common in temperate regions, true ferns are even more 

 abundant in the tropics. 



The stems of our common ferns are rhizomes ; that is, they 

 are underground. They Kve through the winter, growing 



