4 



the back, rarely at the apex of the vein. Indusium usually 

 membranaceous, sometimes wanting. Stipes continuous with 

 the rootstock. Veins usually free. 



8. Cystopteris. Indusium saccate, attached across the 

 fruiting veinlet below the sorus, falling away. ■ 



9. AspiDiuM. Indusium orbicular or reniform, at- 

 tached by a depressed center or at the sinus, opening around the 

 margin. 



10. Phegopteris. Indusium wanting, sori small on the 

 back of free veins near the apex. 



11. Onoclea. Sterile / fronds foliaceous. Fertile frond 

 much contracted into pod or berry like divisions. Indusium 

 rudimentary enclosed with the sorus. 



Tribe V. Woodsieae. Sori round, borne near the middle 

 of the free veins. Indusium spheroidal, attached beneath the 

 sorus, breaking above into spreading segments. 



12. WooDSiA. The only genus. 



Suborder 11. OSMUNDACEAE. 

 Sporangin^naked, globose, usually pedicelled, in panicled clus- 

 ters, opening l<^ngitudiaally. Annulus none or a rudimentary 

 one at the apex. 



Tribe VI. Osmundeae. The only tribe. 



13. Osmunda. Spor.mgia large, numerous, borne upon sep- 

 arate pinnae or fronds. Veins free. 



1. POI^P ODIUM L. Polypody. 

 Low ferns with large round fruit dots. Indusium none. 

 Rootstock creeping, scaly covered and provided with protruding 

 knobs to which the stipe articulates. Fruit dots on the 

 ends of free veinlets, 



P. vulgare L. Fronds 4—6 inches high, oblong, deeply 

 pinnatifid ; divisions alternate, oblong, obtuse, 'minutely 

 toothed, smooth on both sides, green ; fruit dots large, or- 

 bicular, in two rows, midway between midrib and margin, July 

 — October. Grows in the cracks of shaded calcarious cliffs in 

 the eastern river counties. Occasionally found in the interior as 

 in Webster county, etc. 



