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NATURE-STUDY REVIEW [16:6— Sept., 1920 



The Wood Ferns. Dryopteris. Aspidium 



These are our favorite ferns of the shady woods and there are 

 numerous species. The fruiting and the sterile fronds are alike, 

 the spores being borne on the lower side. The species may all 

 be known as belonging to this genus by the shape of the spore 

 blanket, the indusium, which is kidney-shaped and attached 

 to the frond by its concave edge (Fig. 3). Perhaps the two most 

 generally known of the Wood Ferns are the Marginal Shield and 

 the Spinulose. The other species are the 

 New York, the Marsh, the Massachusetts, 

 the Fragrant, the Crested, the Goldies, the 

 Boott's, Shield Ferns, and the IVTale Fern. 

 The Marginal Shield Fern or, as it is 

 often called, the Evergreen Wood Fern is 

 very common from Canada to Arkansas 

 in rocky woods and on wooded banks. It 

 is a large, rather coarse fern, vividly dark 

 green, its pinnae deeply lobed, its fronds 

 from eighteen inches to three feet in height. 

 It may be identified by its fruit dots which 

 ornament the edges of the lobes of the 

 pinnae on the lower side. Just before the 

 spores are shed the spore cases are black 

 and crowd out around the edges of the kidney-shaped indusium. 

 The Spinulose or Spiny Wood Fern. This is exquisitely beauti- 

 ful; its pinnae are deeply lobed and the lobes are toothed and 

 each tooth ends in a little spine which gives a lacey appearance 

 to the frond. Added to its beauty is its keeping quality for it is 

 also evergreen and remains fresh a long time after it is put in a 

 vase. The Boulder Fern resembles this species in form but it 

 wilts as soon as gathered and grows in entirely different situations. 

 The Spiny Wood Fern bears its fruit dots on the under side of the 

 lobe of its fronds, one below a tooth. 



The Triangle Ferns. Phegopteris 



There are three species of the Triangular Ferns and like the 

 Polypody they do not blanket their fruit dots but bear the spore 

 cases naked. Figure 1 shows the broad Beech Fern, la the fruit- 

 ing pinnule. This fern is supposed to like to grow beneath beech 



