CHAPTER VIII 



DIVISION III. PTERIDOPHYTA OR FERNS 



III. Nature of the Ferns. — The members of this division differ 

 greatly in character and Hve under a wide range of conditions, 

 although, like the Bryophyta, they usually frequent moist and 

 shady places, as glens, ravines and damp woods, or in tropical 

 countries they often cover the moist rocks and tree trunks with 

 a luxuriant and attractive vegetation. The most noticeable fea- 



FlG. 213. The Christmas fern, Polystichum, with young leaves uncoiling 

 in the spring at the tip of the stem and further back the fully developed 

 leaves of the past season. The older portion of the stem is covered with 

 the petioles of leaves that have died off and numerous roots are seen arising 

 from the stem and bases of the petioles. — H. O. Hanson. 



311 



