IOWA PTERIDOPHYTA. 163 



following counties: Muscatine (T. H. Macbridc, Sep., 

 1882; Shimck, Oct., 1900; both in full fruit); Jackson 

 (T. H. Macbridc, Aug., 1883, with mature fruit). 



Nephrodium spinueosum (Rets.) Desv. 



Quite rare in the State, two counties only being repre- 

 sented: Johnson (Aug., 1881, sterile); and Muscatine 

 {Fred. Reppert, no date, in fine fruit; Shimck, Oct., 1900, 

 in full fruit; T. H. Macbridc, Sept., 1882, fruiting; De- 

 Jong, Oct., 1894, fruit immature). The last two 

 specimens are clearly the variety intermedium, having the 

 glandular indusium, etc. The other specimens probably 

 also belong to the variety. 



Genus POLYSTICHUM Roth, Tent. Fl. Germ., 

 vol. Ill, (1800). 



POEYSTICHUM ACROSTICHOIDES (Mx .) Sehott . 



Found only in the eastern part of the State, growing on 

 well-shaded banks and slopes. It begins to fruit in 

 August. The following counties are represented in the 

 collection: Jackson (7^. H. Macbridc, Aug., 1883. with 

 mature fruit); Muscatine (T. H. Maebride, Sep., 1882, in 

 full fruit; Shimck, Oct., 1900, in fruit); Johnson (fall, 

 1894, sterile; Aug., 1895, cultivated from a native 

 rootstock) . 



Family ASPLENIE51 J. Smith, Hk. Jour. Bot. (1841). 



Genus ATHYRIUM Roth, Tent. Fl. Germ., vol. I 



(1788). 



Athyrium filix-fcemina (L.) Roth. 



This is probably the most common and most widely 

 distributed fern in Iowa. It is found in more or less 

 shaded places, and varies in size and cutting with the 



