FILICES. 113 



natifid, the lower slightly more distant ; sori medium size, 

 nearly marginal ; indusia more or less toothed at the margin. 

 (Polypodium montanum Vogl., P. oreopteris Ehrh.) British 

 Columbia (Macoun), Unalaska (Turner). 



9. D. NevadensfK (Eat.) Unde. Rootstock creeping, 

 densely covered with the persistent bases of former stalks; 

 stipes short, scaly below ; fronds i 3 long, lanceolate, with 

 pinnae linear-lanceolate from a broad base, and crow Jed seg- 

 ments slightly hairy on the veins and with minute resinous 

 particles ; sori small, nearer the margin than the vein ; indusium 

 minute, furnished with a few dark-colored marginal glands and 

 with jointed hairs on the upper surface. California. 



\ \ Rootstocks stout, erect, forming a short caudex ; fronds in a 

 crown. 



10. D. contermina (Desv.) Ktze., var. strigosa (Fee) 

 Unde. Rootstock often extending a foot above the ground; 

 stipes very stout, narrowly wing-margined near the base ; fronds 

 i 4 long, lanceolate, caudate-acuminate, much narrowed at 

 the base ; pinnae sessile, narrowly lanceolate from a broader 

 base, deeply pinnatifid, the under surface dotted with resinous 

 globules; veins simple; sori near the margin with minute 

 glandular somewhat pilose indusia. Fort Meade, Florida. 



\\\ Rootstocks slender, creeping ; fronds scattered. 



11. D. Noveboracense (L.) Gray. Rootstocks wide creep- 

 ing; fronds i 2 long, 4' 6' broad, tapering both ways from 

 the middle ; pinnae lanceolate, sessile, ciliate, and finely pubes- 

 cent beneath ; veins simple or those of the basal lobes forked ; 

 sori near the margin ; indusium minute, gland-bearing. {Poly- 

 podium Noveboracense L., Aspidium thelypteroides Swz.) North 

 Carolina to Arkansas and northward. 



ft Lower pinna little smaller than those above. 

 \ Veins forked. 



12. D. thslypteris (L.) Gray. Rootstock creeping; fronds 

 lanceolate, scarcely narrower at the base, i 2 long, 4' 6' 

 wide, membranous ; pinnae lanceolate, with obtuse segments 

 which often appear acute from the strongly revolute margin ; 

 veins regularly once or twice forked; sori crowded, 10 12 to 



