8. POLYPODIAGEAE 47 



5. Leaves pinnatifid, the apex caudate, the segments lanceolate, 

 sessile, variable in size, more or less auriculate at the base; 

 on a rocky, wooded hillside along the Mississippi R., near 

 McClure, Alexander Co., E. J. Palmer in 1919; Jackson 

 Co., J. McCree in 1941. Scott's Spleenwort. [Asplenium 

 platyneuron X A. rhizophyllus; Asplenosorus X ehenoides 



(R.R.Scott) Wherry] X A. ehenoides R.R.Scott 



5. Leaves pinnate, with 15-40 pairs of pinnae. 



6. Pinnae auriculate on upper side near base, serrate. 



7. Leaves vmiform, all fertile; pinnae mostly opposite, ellip- 

 tical; rachis black; limestone cliffs, rare; Jackson and 



Union counties. Black Spleenwort A. resiliens Kunze 



7. Leaves dimorphous, the sterile smaller, spreading; pinnae 

 alternate, lanceolate; rachis chestnut-brown; rocky 



woods, not common. Ebony Spleenwort 



A. platyneuron (L.) Oakes 



6. Pinnae crenate, oval, obtuse, not auriculate; sandstone 



cliffs, southern 111., local. Maidenhair Spleenwort 



A. trichomanes L. 



1 1 . Athyrium Roth 



1. Leaves bipinnate or bipinnatifid. 

 2. Leaves bipinnate; pinnules sharply serrate or incised; woods, 

 local. Lady Fern. [A. filix-femiyia ex p. of Am. auth., non L. 



A. angustum (Willd.) Presl 



2. Leaves bipinnatifid; segments crenate-serrate ; woods, not infre- 

 quent. Silvery Spleenwort A. thelypterioides (Michx.) Desv. 



1. Leaves 1 -pinnate; pinnae entire or crenulate, linear-lanceolate, 



acuminate; moist woods, common. Glade Fern 



A. pycnocarpon (Spreng.) Tidestr. 



12. Woodwardia Sm. — Chain Fern 

 W. virginica (L.) Sm. Tamarack bog near Antioch, Lake Co. 



13. Cryptogramma R.Br. 

 C. stelleri (S.G.Gmel.) Prantl. Rock-brake. On damp, usually 

 calcareous rocks, rare; n. 111. 



14. Pellaea Link — Cliff-brake Fern 

 1. Stipes and rachises glabrous or nearly so; leaves 5-25 cm long, pale 



bluish-green; chiefly calcareous rocks, local P. glabella Mett. 



1. Stipes and rachises with numerous jointed hairs; leaves 10-50 cm 



long, grayish-green; dry calcareous rocks, not common; s. 111. 



P. atropurpurea (L.) Link 



15. Adiantum L. — Maidenhair Fern 

 A. pedatum L. Moist woods, fairly common throughout 111. 



