78 EIGHTEENTH REPORT. 



FERN NOTES. 



RV OLIVER ATKINS FARWELL. 



During the past few years as a result of researches in field, 

 herbarium, and library, a number of interesting discoveries and 

 novelties have been brought to light and this paper puts on record 

 some of the results and conclusions arrived at during the course of 

 these studies. 



POLYPODIALES. 



POLYPODIACEAE. 



Pteris aquilina, Linne var. Pseudocaudata, Clute. 



This is a form of the species in which many of the pinnules are 

 narrow, entire, and elongated, particularly the terminal ones. It 

 is only rarely met with. I have found it at Detroit, No. 85161/2, 

 August 10, 1913, in sterile or sandy situations; also on sandy hills 

 at Rochester, No. 25601/0, July 14, 1912. 



Asplenium pinnatifidum, Nutt. 



I have never seen this species in the field but in my herbarium 

 I have a sheet showing several plants which were collected at 

 Cobden, Illinois, by Mr. M. B. Waite, June 8, 1885. These, with 

 the exception of one plant, are normal A. pinnatifidum ; the one 

 abnormal plant is normal in all respects excei)t segmentation 

 which is exactly that of A. ebenoides, R. R. Scott, i. e., the lobes are 

 lanceolate and acute instead of round-ovate and obtuse, and of 

 variable lengths, short and long lobes often alternating. If A. 

 ebenoides is a hybrid between Camptosorus rhizophyllus and As- 

 plenium platyneuron with a trend toward the latter parent, why 

 may not A. pinnatifidum be a similar hybrid with a tendency to- 

 ward the former parent? This peculiar plant would seem to so 

 indicate. 



Asplenium platyneuron (Linne) Oakes. 



A rare fern in Michigan. Real, in the Michigan Flora, states 

 that Allegan is the only station in the State. I found it at Wil- 

 liamstown, Ingliam Co., May 28, 1905, No. 1903. 



Athyrium Felix-femina (Linne) Roth. 



There is a wide degree of variation in the pinnation and size of 

 the different forms tliat liave been referred to tliis si)ecies; the 



