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THE FERN BULLETIN 



examined all my Boottii and found one splendid frond 

 of A r . cristatum X spinulosum collected last June at 

 Lowman, N. Y. It has exactly the appearance of 

 Boottii, but its identity is easily discovered by an ex- 

 amination of the sori. The indusium of spinulosum is 

 distinguished from that of spinulosum intermedium 

 not only by its smoothness but by its lighter color. My 

 Vermont specimen of this same hybrid was not at all 

 like Boottii but totally different from anything I ever 

 saw. 



In the Barton Landing swamp while N. Clintoni- 

 anum is common, typical A r . cristatum is much less so ; 

 and it is interesting to note that Boottii is also rather 

 uncommon. But I found about three plants each of 



N. Clintonianum X spinulosum and A r . Clintonianum 

 marginale. However several elements of doubt are 

 here involved. Many of the Clint onianums seem to me 

 to approach cristatum and some of those called crista- 

 tum X marginale may be Clintonianum X marginale. 



N. Clintonianum X spinulosum andlV. Clintonianum 

 X intermedium, which I did not distinguish from each 

 other while in Vermont, were about as common as N. 

 Clintonianum. But I found later that I had collected 

 about three of the former to one of the latter. That 

 is about 30 of the spinulosum hybrid and about ten of 

 the intermedium hybrid besides some that were sent to 

 Mr. Eaton before making the distinction. It is my im- 

 pression that N. spinulosum intermedium was fully as 

 common as the species. I believe these two hybrids 

 will prove to be rather common. I suspect many of 

 them may be found in herbaria among the Clintoni- 

 anums and Boottii. Mr. Eaton had for several years 

 collected unusual forms of this genus and more than 

 suspected the hybrid origin of some of them. He fre- 



