118 Key to the System of 



581. Fruit-cover opening outward. 



Ferns, oftener dwarf than tall in stature; fruit-cover linear; 

 spore-caselets longitudinally almost surrounded by an 

 often somewhat imperfect ringlet. Figure 141. 



Lindsaya, 2158 



Fruit-cover opening inward. 



Ferns, varying from small to large ; fruit- cover linear ; 

 spore-caselets attached to a filiform receptacle along the 

 base of the fruit-cover, longitudinally almost surrounded 

 by an imperfect ringlet. Figure 145. Pteris. 2159 



582. Fruit-masses parallel to the rhachis of the frond or 



its segments ... ... ... ... ... ... 583 



Fruit-masses diverging from the rhachis of the frond 

 or its segments ... ... ... ... ... 585 



583. Some of the fronds fertile, others sterile, the latter 



broader. 



Ferns, varying from dwarf to tall in stature ; fruit-masses 

 along the rhacheal prominence of their frond or that of any 

 of its segments, much elongated, spreading over nearly 

 the whole frondal under-side ; fruit-cover very elongated ; 

 spore-caselets longitudinally almost surrounded by an 

 often somewhat imperfect ringlet. Figure 146. 



Lomaria. 2165 



Most fronds fertile and all quite similar ... ... 584 



584. Fruit-masses much elongated, always in a single row 



along each side of the rhacheal prominence of the 

 frond or its segments. 



Ferns, oftener tall than dwarf; cover of the fruit-masses 

 membranous, uninterrupted, arising at a distance from 

 the margin of the frond ; fruit-cover very elongated ; 

 spore-caselets longitudinally almost surrounded by an 

 imperfect ringlet. Figure 147. BlecliilUlll. 2170 



Fruit-masses somewhat elongated, in one or two rows 

 at some distance from the rhacheal prominence of 

 the frond or its segments. 



Ferns, generally small ; fruit-cover opening inward ; spore- 

 caselets longitudinally surrounded by an imperfect ring- 

 let. Figure 148. (Doodia.) Woodwardia. 2171 



