i88 



THE LADY FERN AND ITS KIN. 



but except for its fruiting characters, it is more nearly 

 like the species in the latter genus and has therefore 

 been included in this chapter. It is found in low wood- 

 lands in situations similar to those chosen by the silvery 

 spleenwort though seldom if ever so abundant as that 

 species. 



The fronds grow in tufts from a creeping rootstock 

 and sometimes reach a height of four feet, though they 

 are usually at least a foot shorter. They are exceedingly 

 thin and delicate, very sensitive to frosts and are often 

 destroyed by summer storms. The oblong-lanceolate, 

 acute blades are simply pinnate with many long, narrow, 

 entire or crenulate pinnules which taper outward from a 

 rounded, sessile, or shortly stalked, base to the slender 

 tips. The fertile fronds are usually the taller and the pin- 

 nules much narrower with the whole under surface cov- 

 ered by the long, sharply defined sori in two rows along 

 the midrib of each pinnule, much as in the silvery 

 spleenwort. Normally sterile fronds sometimes have a 

 few pinnules that are fertile in which case the spore- 

 bearing parts are narrow like the pinnules of the fertile 

 frond, showing how close is the relationship between 



FRUITING PINNAE. 



