280 Proceedings of the Ohio State Academy of Science. 



I. Poly podium vulgar e L. Common Polypody. 



Rhizome widely creeping, densely covered with brown 

 scales. Leaves evergreen, glabrous, with light-colored petioles. 

 On rock's and rocky banks. General in the eastern half of the 

 state. 



I. Poly podium polypodioides (L.) Hitch. Gray Polypody. 



Rhizome widely creeping covered with small brown scales. 

 Leaves coriaceous evergreen, glabrous or nearly so above, 

 densely covered with gray peltate scales below. On trees or oc- 

 casionally on rocks. Adams and Hamilton counties. 



5. Adiantum L. 



Graceful ferns with much-divided leaves, with polished and 

 shining petioles and dichotomous venation. Sori marginal under 

 the reflexed tips of the pinnules. 



I, Adiantum pedatum L. Maidenhair Fern. 



A fern with dichotomously forked leaves with pinnate 

 branches, and with dark-brown or purplish petioles. On the 

 ground in woods and on rocky hillsides. General and common. 



6. Pteri'dium Scop. 



Large and usually coarse ferns with marginal, continuous 

 sori and indusia and free veins. (Pteris). 



I. Pteridiiim aqniliniim (L.) Kuhn. Eagle-fern. 



Rhizome horizontal and very extensive, the leaves ternate 

 and large with nectar glands in the axils of the main divisions. 

 The nectar is eaten by ants. In sunny places, especially on hill- 

 sides ; sometimes also in the shade. Often called Bracken. Gen- 

 eral in Ohio. 



