No. 14.] FLOWERING PLANTS AND FERNS. 29 



duced and thrives in a pond at Cromwell (C. C. Hanmer), 

 and in Lake Whitney, Hamden. Aug. 



EQUISETACEAE. HORSETAIL FAMILY. 

 EQUISETUM L. Horsetail. Scouring Rush. 

 Equisetum arvense L. (of cultivated ground). 

 Common Horsetail. 



Common. Sandy soil either dry or moist. Varies greatly 

 according to season or habitat and several forms have been 

 described. Fertile May ; sterile June. 



The plant is medicinal. It is said to be dangerously poison- 

 ous to horses when cut with hay. 



Equisetum pratense Ehrh. (of meadows). 



Rare. Moist sandy alluvium on the banks of the Housa- 

 tonic River: Oxford (Fames & Harger), Newtown (Harger). 

 Fertile May ; sterile June — July. 



This resembles the preceding species and may have been 

 overlooked by other collectors. 



Equisetum sylvaticum L. (growing in woods). 



Occasional or local. Moist places and in wet ground about 

 springs. Fertile May ; sterile June — July. 



Equisetum palustre L. (of marshes). 



Rare. Wet meadows along the Connecticut River or on 

 its banks: Lyme (Graves), East Windsor (Bissell). June. 



Equisetum fluviatile L. (of a river). 

 Equisetum limosum L. 

 Pipes. 



Shallow water and wet meadows along streams. Frequent 

 along our rivers and larger streams but rare or local else- 

 where. Fertile May; sterile June — Aug. 



Equisetum hyemale L. (lasting over the winter), var. inter- 

 medium A. A. Eaton (intermediate). 

 Scouring Rush. 



Rare. Growing on railroad embankments: Hartford (H. 

 S. Clark), Norfolk (Bissell & H. S. Clark). May —June. 



