:274 Proceedings of the Ohio State Academy of Science. 



2. Leaf blades compound or somewhat lobed, the sporangia on the 



blade or on distinct leaves. 3. 



3. Leaves rooting freely at the long tapering apex, simple or somewhat 



lobed ; sori linear or oblong ; vascular bundles in base of petiole 

 "2 Camptosoriis (11). 



3. Leaves not rooting at the tip, pinnatifid or pinnate. 4. 



4. Sterile pinnae sharply serrate; vascular bundles in base of petiole 



2 or numerous, sori oblong in chain-like rows ., 



Woodzvardia (8) . 



4. Sterile pinnae coarsely toothed or lobed; vascular bundles in base 



of petiole 2; sori round, enclosed in the leaflet Onoclea (19). 



5. Vascular bundles in base of petiole 3 or more. 6. 



5. Vascular bundles in base of petiole 1 or 2, but additional brown 



or black sclerenchyma bundles may be present. 11. 



6. Sporangia on a more or less branched sporangiophore distinct from 



the leaf blade : vascular bundles in the base of the common 

 petiole in a ring Bofrychinm (2) . 



6. Sporangia not on a sporangiophore distinct from the leaf blade. 7. 



7. Leaflets with continuous marginal indusia ; leaves large, ternate, 



with nectar glands in the axils of the main divisions; vascular 

 bundles in base of petiole about 12, irregularly arranged.. . 

 Pteridium ( 6 ) . 



7 . Sori with special indusia or naked, not covered by the leaf margin ; 



vascular bundles in base of petiole 10 or less. 8. 



8. With oblong or linear sori in chains parallel to the midrib; leaf- 



lets areolate in the middle; vascular bundles in base of petiole 7-9. 

 Woodwardia (8) . 



8. Sori round or roundish, indusia less than twice as long as broad. 9. 



9. Pinnae strongly auricled on the upper side at the base; fertile part 



of leaf specialized; indusium orbicular, peltate, without a sinus, 

 fixed by the centre ; vascular bundles in base of petiole 4-5. 



Polysfiduim (12). 



9. Pinnae not auricled. 10. 

 10. Leaves simply pinnatifid ; petioles articulated to the rhizome; sori 

 naked, circular: vascular bundles in base of petiole 3... 

 Polypodium (4). 



10. Leaves 2- or more- pinnatifid or pinnate; indusium reniform or if 



orbicular with a narrow sinus Dryopteris (18). 



11. Sporangia borne on specialized leaves, without foliage leaflets, on 



specialized pinnae at the middle or end of the foliage leaf, or 

 on special sporangiophores distinct from the leaf blade. 12. 

 11. Sporangia on leaflets of ordinarj^ foliage leaves, some or ail of 

 which niav be fertile. 14. 



