POLYPODIACEAE. 



421 



1. Anchistea virginica 

 (L.) Presl. VIRGINIA CHAIN- 

 FERN. (Fig. 457.) Eootstock 

 stout, chaffy. Petioles stout, 

 1-1 long, nearly or quite 

 naked, dark-colored below ; 

 blades oblong-lanceolate, acute, 

 narrowed at the base, l-2 

 long, 6'-9' wide, once pinnate ; 

 pinnae linear-lanceolate, usually 

 alternate, or some of them op- 

 posite, leathery, glabrous, acu- 

 minate, sessile, 2?'-6' long, 

 deeply pinnatifid into ovate or 

 oblong obtuse segments, their 

 margins minutely serrulate. 

 [Blechnum virginicum L. ; 

 Woodwardia virginica J. E. 

 Smith.] 



Frequent in the larger fresh- 

 water marshes. Native. Eastern 

 North America. 



8. ASPLENIUM L. 



Large or small ferns with entire lobed pinnate, 2-3-pinnate, or pinnatifid 

 leaves, and linear or oblong sori oblique to the midribs or rachises. Leaves 

 mostly uniform. Veins free. Indusia straight or curved, .opening toward the 

 midribs. [Ancient Greek name; some species were supposed to be remedies 

 for diseases of the spleen.] A genus of some 400 species, of very wide 

 geographic distribution. Type species: Asplenium Trichomanes L. 



Leaves once pinnate. 



Pinnae 6-8 pairs ; stipes blackish only at the base. 



Pinnae 20-40 pairs ; stipes black, shining. 

 Leaves finely twice or thrice pinnate. 



1. A. dentation. 



2. A. hcterochroum. 



3. A. 



