196 BOTRYCHIUM 



RATTLESNAKE FERN: 



Botrychium virginianum. 



The rattlesnake fern consists of a single stalk, 

 surmounted by a single frond, which is divided 

 into a sterile and fertile portion. The sterile part 

 is broadly triangular^ the lowest pair of pinnae be- 

 ing so large as to appear as if the frond were di- 

 vided into three principal divisions. The fertile 

 portion, which rises above the sterile, discharges its 

 spores early, and withers often by July. Many 

 plants are sterile. 



A solitary species, sometimes 3 feet in height, but 

 commonly much less, found in shaded woods; 

 widely distributed throughout the United States. 



NOTES. 



