West Indies and southward to Brazil. This 

 species is as well placed in the genus Phegop- 

 teris. — Dryopteris reptans (Gmel.); Aspidium 

 reptans (Gmel.) ; Pliegopteris reptans (Gmel.). 



1 1 8. Nephrodium rigidum argutum (Kaulf.). Not com- 



mon. Arizona and California to Alaska, mostly 

 near the coast. The type is found from Great 

 Britain to the Mediterranean region. — Dryop- 

 teris rigida arguta (Kaulf.); Aspidium rigidum 

 argutum (Kaulf.). 



119. Nephrodium setigerum (Bl.). Rare; in swampy 



woods. Southern Florida; also throughout the 

 tropics. — Dryopteris setigera (Bl.). 



120. Nephrodium simulatum Dav. Rare; in shaded 



bogs. Maine to New York and Maryland. — 

 Dryopteris simulata Dav. ; Aspidium simulatum 

 Dav. 



121. Nephrodium spinulosum (Mull.). Spinulose Wood 



Fern. Common; in rocky woodlands, espec- 

 ially if moist. Newfoundland to Virginia, Ken- 

 tucky, Nebraska, Washington and Alaska; also 

 in Europe and Asia. — Dryopteris spinulosa 

 (Mull.); Aspidium spinulosum (Mull.). 



The form concordianum Dav. is a finely di- 

 vided form possibly referred to the sub-species 

 intermedium ; f. fructuosum Gilbert is a heavily 

 fruited form from New York and New Eng- 

 land, also referred to the sub-species; f. Pitts- 

 fordense is an ecological form from New York 

 and New England. 



122. Nephrodium spinulosum intermedium (Muhl.). 



Common Wood Fern. Abundant; in moist, 

 usually rocky, woods. The common form 

 within the limits given for the type. — Dryopteris 

 spinulosa intermedia (Muhl.); Aspidium spinu- 

 losum intermedium (Muhl.). 



