Proceedings of the Ohio State Academy of Science. 285 

 13. Dryopteris. Adans. Shield-fern. 



Ferns with 2-3-pinnate or pinnatifid leaves and round sori 

 with cordate-reniform indusia. Veins free; petioles not jointed. 

 {Aspiditim). 



1. Vascular bundles of petiole 2, free or united; veins simple or once 

 forked ; leaves thin-membranous. 2. 



1. Vascular bundles 5 or more; veins forking freely; texture of the leaf 



firmer. 3. 



2. Lower pinnae very much reduced; vascular bundles usually 



bridged D. noveboracensis. 



2. Lower pinnae little smaller than the middle ones; veins once forked; 



vascular bundles 2, distinct D. thelypteris. 



3. Leaves 2-pinnatifid or 2-pinnate, the segments not spinnulose 4. 



3. Leaves 2-pinnate or 3-pinnatifid, the segments spmulose-toothed. 6. 



4. Sori marginal; petiole densely scaly below; indusia con- 



vex D. marginalis. 



4. Sori not marginal; petiole with few scales; indusia flat and 



thinnish. 5. 



5. Vascular bundles in petiole 5; pinnae widest at the base. 



D. cristata. 



5. Vascular bundles in petiole 7; pinnae widest at the middle. 



D. goldieana. 



f). Leaves ovate-lanceolate, usually not narrowed below..../?, spinulosa. 



6. Leaves elongated-lanceolate, usually narrowed at the base..D. boottii. 



1. Dryopteris noveboracensis (L.) Gr. New York Shield- fern. 



Rhizome slender and creeping; leaves lanceolate, tapering 

 both wa}'s from the middle, r-2 feet long or more, petioles more 

 or less chaiTy. On the ground in moist woods. General. 



2. Dryopteris thely'pteris (L.) Gr. Marsh Shield-fern. 



Rhizome slender and creeping ; leaves lanceolate or oblong- 

 lanceolate, scarcely narrower at the base than at the middle, 

 usually two to four feet long. In swamps and marshes. General. 



3. Dryopteris cristata (L.) Gr. Crested Shield-fern. 



Rhizome stout and densely chaffy; leaves evergreen, linear- 

 oblong or lanceolate, acuminate, gradually and slightly narrowed 



