20 



as a hybrid between N. spinulosum and N. 

 cristatum. Forma multiflorum Gilbert is a 

 larger, more heavily fruited form occurring 

 with the type. — Dryopteris Boottii (Tuekerm.); 

 Aspidium Boottii Tuekerm. 



104. Nephrodium conterminum strigosum (Fee). Rare; 



in woods. Ft. Meade, Florida. The type is 

 common in the West Indies. — Dryopteris conter- 

 mina strigosa (Fee) ; Aspidium conterminnm 

 strigosum D. C. Eaton. 



105. Nephrodium cristatum (L-)- Crested Fern. 



Common; in swamps, especially in shade. 

 Newfoundland to Virginia, Arkansas, Ne- 

 braska, Idaho and the Northwest Territory; 

 also in central and northern Europe and west- 

 ern Siberia. — Dryopteris cristata (L.); Aspid- 

 ium cristatum (L.). 



The form marginale Dav. is reported from 

 New England and New York ; f. Lancastricnse 

 (Spreng.) from the same region has the lobes 

 of the pinnae shorter and approaching triangu- 

 lar. Two hybrid forms are credited to this 

 species — N. cristatum X marginale Dav. from 

 New England, New York and New Jersey, and 

 N. cristatum X spinulosum (Milde), the latter 

 better known in America as N. Boottii. 



106. Nephrodium cristatum Clintonianum (D. C. Eaton). 



Somewhat rare; in moist shades. Maine and 

 Ontario to Wisconsin and Virginia. A much 

 larger form than the type and found with it. — 

 Dryopteris cristata Clintoniana (D. C. Eaton); 

 Aspidium cristatum Clintonianum (D. C. Eaton). 



107. Nephrodium Filix-mas (L.). Male Fern. Some- 



what rare; in woodlands. Newfoundland, Nova 

 Scotia and Alaska to Vermont, Michigan, South 



