THE FERN BULLETIN 



17 



common in the pools of stagnant water characteristic 

 of the rolling plains of the region. I regret the short- 

 ness of this list but doubt if it could be extended very 

 much. — F. C. Green, Ncz^ Albany, Indiana. [The 

 species enclosed is Marsilia vestita, the water-clover, 

 found from Dakota to Texas in suitable places. — Ed-] 



Botrychium dissectum. — For some years there 

 has been much discussion for and against the specific 

 distinctness of the cut-leaved grape fern. This dis- 

 cussion has been mostly the arguments of theorists. 

 On the one hand it id contended that any fern so 

 nearly like another, in general form, time of growth, 

 production of spores, sizee and habitat, as the dissected 

 form is to the common one and which only differs in 

 the cutting of the ultimate segments must certainly be 

 a mere form of it ; on the other hand it is asserted that 

 since it keeps its form, is practically the same whenever 

 found and does not apparently intergrade it must be a 

 good species. Unfortunately the difficulties attendant 

 upon the rearing of these plants from spores, while not 

 insuperable are sufficient to prevent, at least thus far, 

 any experimental proof of their specific distinctness. 

 The prothallia are tuberous, subterranean, and sym- 

 biotic having set up a partnership with some sort of a 

 fungus. Apparently they cannot be grown to 

 maturity without their attendant fungi. Some 

 faint light has been shed upon the problem, 

 however, by a writer in Ohio Naturalist who 

 notes that the very first leaf from the pro- 

 thallium shows the dissected form. This would go 

 some distance toward proving this plant a good species 

 for it is well known that in a great number of plants 

 which differ markedly at maturity, the juvenile leaves 



