GROUP IV 



FERTILE AND STERILE FRONDS LEAF-LIKE AND SIMILAR ; 



SPORANGIA ON OR BENEATH A REFLEXED PORTION 



OF THE MARGIN 



20. BRAKE. BRACKEN. EAGLE FERN 



Pteris aquilina 



Almost throughout North America, in dry, somewhat open 

 places. One to two feet high ordinarily, occasionally much higher. 



Fronds. — Solitary, one to two feet wide, cut into three primary 

 divisions which are twice-pinnate, widely spreading at the summit 

 of an erect, stout stalk ; sporangia borne in a continuous line 

 along the lower margin of the frond ; indusium formed by the 

 reflexed edge of the frond. 



Of all ferns the Brake is the most widely dis- 

 tributed. It occurs in one form or another in all 

 parts of the world. With us it grows commonly 

 from one to two feet high, occasionally higher. In 

 Oregon it attains a height of six or seven feet, in 

 the Andes of fourteen feet. 



It is a vigorous and often a beautiful and striking 



plant, growing abundantly on sunny hillsides and 



in open woods. 



loS 



