THE WOOD FERNS. 



139 



undergrowth. It is not generally distributed in its range, 

 is often rare or missing over large stretches of coun- 

 try, and is seldom as plentiful as marginale. It is easily 

 cultivated and its stately fronds form a valuable addition 

 to the fern garden. 



A form of this fern, from the Dismal Swamp has been 

 described as the variety celsum. It differs from the type 

 in being narrower, more erect and with pinnules and 

 pinnae further apart. 



'The Crested Fern. 



When one's rambles happen to take him through a 

 piece of wooded swamp full of hellebore and skunk's 

 cabbage, where early in the season the marsh marigold 

 and spring beauty cover the earth with bloom and later 

 in the year the Canada lily hangs out its orange-yellow 

 bells, he is likely to come upon the crested fern (Aspidium 

 cristatuni) with its tall narrow fertile fronds quite erect in 

 the dim light, as if disdaining the mud in which it is 

 rooted. But this is in summer. If one passes that way 

 again in winter, no fertile fronds are to be seen, but the 

 sterile still remain, fresh and green, though prostrate on 

 the frozen ground and scarcely recognised as belonging 

 to the same plant. 



Few species make a more striking distinction between 

 sterile and fertile fronds. It seems to have the nature of 

 two plants in one. The fertile fronds are tall, erect, and 

 found only in summer ; the sterile are shorter, spreading 

 and conspicuous only in the winter. In both, the outline 

 is narrowly oblanceolate and acute, and both are pinnate. 

 The pinnae are broadest at the base, the lowest pairs al- 

 most triangular and the upper tapering outward to the 

 tips. All are deeply cut into close, broad, obtuse pin- 



