FILICES. 1 1 1 



peltate, fixed by the depressed centre ; pm7tce a7id pinnules usually 



auricled on the upper side at base, iiiucronately 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. incisiun Gray. {Nephrodiiini 

 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, 1° — 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 {Stiksdorf), and northward. 



** Fronds bipitinate 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 sliglitly 

 toothed oblong rhomboidal pinnules; teeth blunt or mucro- 

 nate ; texture coriaceous; both surfaces naked; rachis stout 



