THE FERN BULLETIN 



43 



ISOETACEAE. 



Isoetes melanopoda (J. Gay.) "Muddy borders of 

 a pond near Hyde Park water- works, 1885. Wet 

 prairies near Grand Crossing, 1886-87." Higley and 

 Raddin. These stations in Cook county are doubt- 

 less destroyed now. Stark county, V. H. Chase. 

 "Menard, Hall; Fulton, Wolff; McHenry, Vasey" 

 (P.) 



Isoetes Butleri (Engelm.) "Moist hillsides and 

 shallow depressions, Illinois and Kansas to Tennes- 

 see and Oklahoma. " Gray's New Manual of 

 Botany. 



A PROBLEMATICAL FERN. 



(Gymnogramma lanceolata.) 



By Willard N. Clute. 



In the identification of fern species one occasionally 

 comes upon two forms so nearly alike that it requires 

 very careful study to decide whether they are two dif- 

 ferent species or merely two forms of a single variable 

 species, but it is rare that one finds a fern that can as 

 well be placed in one genus as another, and still more 

 rare when the species possesses characters so like those 

 of ferns in other groups that it may be moved from 

 one tribe to another without violating any of the 

 botanical properties. The fern chosen for illustration 

 here is one of this latter character. It has been passed 

 back and forth between various genera in different 

 tribes, seldom resting long in one place, until it is a 

 very problematical species indeed. 



In outline and manner of growth it possesses no espe- 

 cial peculiarities. The lanceolate leaves might fit any 

 of a dozen or more species that might be mistaken for 

 it if the fruit dots, or sori were absent. Vittaria,, Tae- 



