66 Our Native Ferns. 



- i 



H. 



K. 



[Fronds conspicuously dimorphous ; stipes light- 

 colored, . IX. 



i Fronds nearly uniform ; stipes usually dark, . G. 



' Sori on the upper part of the veins, mostly form- 

 ing a continuous marginal band ; indusium 

 membranous, continuous round the segment, X. 



G. -| Sori minute, at the ends of the veins ; indusium 

 interrupted or if continuous, the ultimate seg- 

 ments usually small and bead-like ; fronds most- 

 ly chaffy, woolly, or farinose, . VIII. 



I 



M. 



' Sori roundish ; indusia not more than twice as 



long as broad, . .... I. 



Sori linear or oblong ; indusia more than twice 

 j as long as broad, . . L. 



Indusium superior, attached by the centre or 

 sinus, ... J. 



I Indusium convex, fixed by a broad base partly 



under the sorus, . . XXI. 



[Indusium inferior, . K. 



C Sori mostly on the back of the veins; indusium 

 orbicular or reniform, opening all round the 



margin . XIX. 



Sori at the endof afree vein; indusium reniform, 

 opening toward the margin of the frond ; fronds 

 simply pinnate, the pinnze articulated to the 

 rachis, . ... . XX. 



f Indusium roundish or stellate, delicate, . XXIII. 



1 Indusium cup-shaped, somewhat two-valved, . . XXIV. 



Sori all parallel to the midribs or rachises, . . M. 

 Sori all oblique to the midribs, ... O. 

 Sori partly oblique and partly parallel to the mid- 

 rib ; frond simple, tapering to a point, . . XVII. 



f Veins free, .... N. 



I Veins reticulated, . XIV. 



