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Woodsia obtusa Torr. Calcareous cliffs, infrequent in the 

 eastern half of the State. 



Woodsia scopulina D. C. Eaton. Specimens in our collection 

 are from Lyon county, collected by Prof. Shimek. 



EQUISETACE.^E. 



Bquisetum arvense L. Field horsetail. Moist soil, com- 

 mon throughout the State. The fruiting specimens appear in 

 early spring, shed their spores, and soon wither away ; the sterile 

 stems flourish the summer long. No fruiting specimens were 

 to be found during the spring of 1902, although we searched 

 localities which furnished them innumerable during other sea- 

 sons. Our belief is that the severe freeze after the season 

 opened caused all the fertile shoots to be killed. 



Bquisetum pratense Ehrh. Specimens of this species were 

 collected by Prof. Shimek in Dubuque and Clayton counties. 



Bquisetum sylvaticum L. Wood horsetail. Specimens in our 

 collection are from Jasper county, collected by Prof. Norris, 

 who writes under date of February 26, 1896 : "About ten years 

 ago I found Bquisetum sylvaticum near here [Grinnell, Iowa]. 

 It was extremely local and has since been exterminated by 

 hogs." 



Bquisetum Auviatile L. Rather widely distributed over the 

 northern half of the State. 



Bquisetum robustum A. Br. Damp soil, frequent. 



Bquisetum Jiycmalc L. Scouring rltsh. This =pecies is prob- 

 ably frequent. Formerly Iowa collectors included B. robustum 

 with it, hence at present there is more or less confusion. 



Bquisetum lacvigatum A. Br. Gravelly clay soil, frequent 

 throughout our area. 



LYCOPODIACE/E. 



Ly cop odium clavatum L. Common club moss. Rare. The 

 only Iowa material we have of this species was collected in 

 Johnson county, fifteen years ago. 



Lycopodium complanatum h. Our Iowa material is from 

 Johnson county, where it is rarely collected. The species has 

 been found in Muscatine county. 



Lycopodium lucidulum Michx. Muscatine county. Ferdinand 



