54 WOODSIA. 



WOODSIA. 



Sori on the back, in round masses. Indusium 

 attached under them, and splitting above 

 into hair-like divisions or fine threads. 



WOODSIA HYPERBOREA. (Round-leaved Woodsia.) 

 Fig. 20. From 2 to 4 inches. Root tufted. 

 Growing in masses. Pinnse mainly alter- 

 nate, short, blunt, wide, triangular ly- 

 formed, and rounded into little scallops 

 above and below, the superior being a trifle 

 the largest. Under surface covered with 

 hairy scales. Sori marginal, full-sized ; 

 ultimately uniting. May. Deciduous. 

 Difficult of cultivation. Very rare. 

 Northern. Of no particular beauty or 

 interest. 



ILVENSIS. (Oblong Woodsia.) Fig. 22. 



From 2 to 4 inches. Root tufted. Growing 

 in masses. Pinnae slightly alternate, ob- 

 long, rather tapering, deeply and widely 

 incised, rounded at the incisions, and 

 hairy. In the larger, running into dis- 

 tinct pinnulets. Under surface clothed 

 with reddish, chaffy, scales. Sori smaller, 

 scattered, towards the margin, and even- 

 tually uniting. May. Deciduous. Very 

 rare. Northern. Difficult of cultivation, 

 and of no peculiar interest. 



