FILICES. lOQ 



2. P. hexagonoptera Fee. Stipes 8' 18' long, stramine- 

 ous, naked; fronds as broad as long or nearly so, 7' 12' long, 

 slightly pubescent, and often finely glandular beneath ; upper 

 pinnae oblong, obtuse, toothed or entire, the very large lowest 

 pinnae elongate and pinnately lobed ; sori near the margin or 

 some between the sinus and the midrib. (Polypodium hexagon- 

 opterum Michx.) Canada to Illinois, Kentucky, and Florida. 

 ** Fronds oblong-lanceolate, tripinnatifid; rachis wingless. 



,^3. P. alpestris Mett. Rootstock short, thick, erect or ob- 

 lique; stipes 4' 10' long, with a few brown spreading scales 

 near the base ; fronds i 2 long, pinnae deltord-lanceolate, the 

 lower ones distant and decreasing moderately; pinnules oblong- 

 lanceolate, incised and toothed; sori small, rounded, sub- 

 marginal. (Polypodium alpestre Hoppe, Aspidium alpestre 

 Swz.) California and northward. 



*** Fronds ternate,the three divisions pet ioled; rachis wingless. 

 ^4. P. dryopteris Fee. (OAK-FERN.) Rootstock slender, 

 creeping; fronds broadly triangular, 4' 8' wide; the three 

 primary divisions i 2 pinnate; segments oblong, obtuse, entire 

 or toothed ; sori near the margin. (Polypodium dryopteris L., 

 Nephrodium dryopteris Michx.) Northeastern United States to 

 Virginia, and westward to Oregon and Alaska. 

 Var. Robertianum Dav. Stipes 6' 10' long, stramineous 

 when dry, glandular; fronds 6' 8' long, 5' 7' wide, deltoid- 

 ovate in outline, bipinnate, lowest pair of pinnae far the largest, 

 pinnatifid or again pinnate; upper pinnae smaller, pinnatifid, 

 lobed, or entire ; sori copious, forming submarginal rows around 

 the segments. (P. calcarea Fee.) Minnesbta (Cat heart), Deco- 

 rah, Iowa (Hohvay), Northeast Territory (Macoun). 



2. GONIOPTERIS Presl. Veins pinnate, the lower veinlets 

 of contiguous groups uniting. 



5. P. tetragona Fee. Rootstock creeping; stipes erect, 

 6' 18' long, naked or slightly villose ; fronds i 2 long, 

 6' 12' broad ; pinnae numerous, spreading 3' 6' long, the lowest 

 narrowed at the base and sometimes stalked, deeply pinnatifid ; 

 texture thinly herbaceous; rachis and under surface finely pu- 

 bescent ; sori in rows near the midrib. Marion County, Florida 

 {Reynolds). 



