284 Proceedings of the Ohio State Academy of Science. 



1. Athyrium thelypterbides (Mx.) Desv. Silvery Spleenwort. 



A large fern with sinuous, creeping, rhizome. Leaves 

 lanceolate in outline ; petiole straw-colored, somewhat chaffy 

 below. Segments of the pinnae blunt, scarcely crenate. {As- 

 pleniuni acrostichoides Sw.). In rich moist woods. General 

 in Ohio. 



2. Athyrium filix-fdemina (L.) Roth. Common Lady-fern. 



A large graceful fern with a rather slender creeping rhizome. 

 Leaves broadly oblong-ovate or oblong-lanceolate, acuminate at 

 the apex ; pinnules oblong-lanceolate, mcised or serrate. On 

 the ground in rich moist woods and more open places. General 

 in the state. 



II. Camptosorus Link. Walking-fern. 



Slender evergreen ferns with tapering simple leaves rooting 

 freely at the tips. Venation reticulate ; sori linear or oblong. 



I. Camptosorus rhisophy'llus (L.) Link. Walking-fern. 



Rhizome chaffy, short, usually creeping ; petioles light green ; 

 leaves auricled, the auricles sometimes rooting. On rocks, es- 

 pecially limestone. General in Ohio. 



12. Poly'stichum Roth. 



Coarse pinnate or bipinnate ferns with an erect or creeping 

 rhizome and round sori. Lidusium orbicular, superior, peltate ; 

 petiole not jointed; veins free. 



I. Polvstichufu acrostichoides (Mx.) Schott. Christmas Fern. 



An evergreen fern with a stout, creeping rhizome. Leaves 

 once pinnate, petioles densely chaffy, pinnae half-halberd-shaped. 

 Fertile leaves contracted at the summit. In woods and rocky 

 places. General in Ohio. 



The form, P. acrostichoides schweinitsii (Beck.) Small, has 

 toothed or pinnatifid pinnae and has been found in Wayne county. 



