274 ProcccdiJigs of the Ohio State Academy of Science. 



1. Leaf blades conipuuiul or somewhal luljcd, Uic sporangia on the 

 blade or on distinct leaves. 3. 



3. Leaves rooting freely at ibc long ta])ering a]K'x, simple or somewhat 

 lobed; sori linear or oblong; wiseular bnndles in base of i)ctiole 

 ■_' CainpldSdnis (11). 



3. Lea\'es not rooting at the tip, ])innaliii(l (ir jjinnatc. -1. 



4. Sterile pinnae sharply serrate; vascular bundles in ba^e of petiole 



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



Wiiodzciinlia (8). 



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



of petiole "J; sori round, enclosed in the leaflet (Jinu'lra (19). 



5. Vascular bundles in base of petiole 3 or more. (i. 



'i. \'ascular bundles in base of petiole 1 or 2, but additional brown 

 or black sclerenchyma bundles may be present. 11. 



ti. Sporangia on a more or less Ijranched sporangiophore distinct from 

 the leaf blade: Aascular bundles in the base of the conunon 

 petiole in a ring Botrycliium {'!) . 



(J. 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 abont 1"_', irregularly arranged.. . 

 Ptcridiitm (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. 

 JJ'oodzvardia (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, 

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



Pulysticliiini ( 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 i)innate; indusium reniform or if 



orbicular with a narrow sinus Dryopteris (13). 



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 ordinary foliage leaves, some or all of 

 which mav be fertile. 14. 



