FILICES. 1 1 1 



peltate, fixed by the depressed centre ; pinnce and pinmiles usually 

 auricled on the upper side at base, mucronately serrate ; veins free. 



* Fronds simply pinnate. 

 t Fronds long-stalked, lanceolate. 



3. D. acrostichoides (Michx.) Ktze. (CHRISTMAS-FERN.) 

 Stipes 6' 8' long, clothed below with pale-brown lanceolate 

 scales ; fronds i 2 high, 3' 5' broad ; pinnae linear-lanceolate, 

 somewhat falcate, half-halberd-shaped at the base, serrulate 

 with appressed bristly teeth ; the fertile ones contracted and 

 smaller, bearing contiguous sori near the middle, soon covering 

 the entire surface. A form with cut-lobed, often strongly fal- 

 cate pinnae, set obliquely to the rachis, and with the tips of 

 nearly all bearing sori, is the -var. tncisum Gray. (Nephr odium 

 acrostichoides Michx.) New England to Florida, Mississippi, 

 and northward. 



4. D. munita (Kaulf.) Ktze. Stipes 4' 12' long, chaffy, the 

 rachis with brown scales; fronds growing in a crown, i 4 

 long, tapering slightly toward the base; pinnae numerous, 

 linear-acuminate, 3' 4' long, very sharply and often doubly 

 serrate, with appressed needle like points; sori numerous, 

 forming a single row each side of the midrib half-way to the 

 margin. California and northward. 



ft Fronds scarcely stalked, linear-lanceolate. 



5. D. lonchitis (L.) Ktze. (HOLLY-FERN.) Fronds 9' 20' 

 long, rigid ; pinnae i' or more long, broadly lanceolate-falcate or 

 the lowest triangular, strongly auricled on the upper side, the 

 lower obliquely truncate, densely spinulose-toothed ; sori con- 

 tiguous and near the margin. Canada and Wisconsin to Utah 

 (Jones), Castle Lake, Siskiyou County, California (Pringle], Mt. 

 Peddo, Washington (Suksdorf), and northward. 



** Fronds bipinnate or nearly so. 



6. D. mohrioides (Bory) Ktze. Stipes 2' 6' long, more 

 or less densely clothed with lanceolate dark-brown scales ; fronds 

 6' 12' long, 2' 3' broad, with numerous dense, often imbri- 

 cated, lanceolate pinnae, which are cut below into slightly 

 toothed oblong rhomboidal pinnules; teeth blunt or mucro- 

 nate ; texture coriaceous; both surfaces naked; rachis stout 



