FERN FLORA OF N0RTHEASTJ5RN IOWA 421 



Polypodiunv vulgare L. Allamakee and Clayton counties. 

 C'iiffs, frequent, even common on shaded outcrops of St. Peter 

 sandstone in Allamakee county and on the "pictured rocks", at 

 McGregor, Clayton county. The species has been reported also 

 from Winneshiek county. 



SALVINIACE^. 



Azolla caroliniana Willd. This species is found floating in 

 quiet waters. It was found by Miss King in Allamakee county 

 (Plant World, 5:225). The writer has specimens from Musca- 

 tine and Louisa counties, from hayous along Mississippi river, 

 fc-rther south than the region under consideration. There are in 

 hand, also, specimens collected by J. P. Anderson from Lake 

 Waib'onsi in Fremont county, the southwest corner county of 

 the state. This species is rarely collected but it is probably 

 more freqnent than collections indicate, being overlooked. 



EQUISETACE^. 



Equisetum arvense L. Moist sandy or clay soils, w^aysides 

 and waste places, common ; Winneshiek, Allamakee, Clayton, 

 and Dubuque counties. This species is extremely abundant on 

 islands of Mississippi river, in many cases gro'wing in the water. 



Equisetum laevigatum A. Br. Coimnon in moist clayey soil, 

 along waysides and banks; Winneshiek and Allamakee counties. 



Equisetum robtistiim A. Br. This species has: been found in 

 Winneshiek, Clayton, Dubuque, Clinton, and Jackson counties. 

 It occurs abundantly in moist to wet soil, along banks. 



Equisetum liyemale L. Specimens from Winneshiek, Allama- 

 kee, and Dubuque counties have been referred here. 

 LYCOPQDIACE^. 



Lycopodium lucidulum Michx. This species has been found in 

 moist woods near Hesper, Winneshiek county. 

 SELAGINELLACE^. 



Selaginella rupestris (L.) Spring. Dry rocky soil; plentiful 

 ait least locally; Winneshiek and Dubuque counties. 



ISOETACE^. 



Isoetes melanopoda J. Gay. This species has been collected in 

 Clinton county. 



The Univeksity of Nebraska, 

 Station A, Lincoln. 



