— 8— 



had been held by me almost from its discovery four years ago. 

 From its habit of growing only in places so shady that other 

 plants do not thrive, I propose to name it as follows : 



Botrychium tenebrosum n. sp. Height, i-q inches, averag- 

 ing 4 or 5 inches, one- third of which is below ground; slender, not 

 fleshy, light green or yellowish after fruiting, transparent when 

 dry; vernation as in B. lunar ia\ sterile lamina above the middle, 

 often immediately under the fertile, short-petioled, simple, lobed 

 or usually with 1-3 pairs of distant, alternate, lunate, decurrent, 

 entire segments ; apex, emarginate or with a triangular elonga- 

 tion of the rachis. Fertile division usually short-stalked, simple, 

 or rarely with one or two short branches, somewhat dilated, bear- 

 ing alternate or nearly opposite clusters of sporangia on the sides, 

 spores, very large, verrucose. Habitat, rich shady situations, 

 usually among maples at the border of swamps ; common in Rock- 

 ingham County, N. H.,and Essex County, Mass. Found at Tarn- 

 worth, N. H., Miss Hutchinson; and at Jackson, N. H., Davis and 

 Fuller. Mr. Davenport has specimens in his herbarium collected 

 by him in a cedar swamp at Charlotte, Vt. 



Though common, this plant is often overlooked because so 

 small, and it .has doubtless been referred when collected to either 

 B. simplex or B. tnatricaricefolium. The differences between 

 this and the former have been set forth in a paper presented at 

 the meeting above referred to. It may be separated from the 

 latter, briefly, by its small size, texture, vernation, once pinnate 

 sterile, and undivided fertile divisions, and the large spores, 

 which exceed those of simplex in size. 



Seabrook, N. H. 



ADAPTABILITY OF FERNS TO LIGHT. 



SERIES of experiments, carried on with reference to the 



amounts of sunlight needed by different ferns and their 



adaptability to varying amounts of sunlight, would be of 

 much interest. Even closely related species differ markedly in 

 this respect. Dryopteris simulata thrives only in very shady 

 places, but its near relative, D. Thelypteris, requires much sun- 

 light, and is at its best in an open swamp. Woodwardia Vir- 

 ginica, when growing in sunny places, has comparatively broad 

 pinnai and pinnules which are set rather closely together. In 

 shady places everything becomes narrower, and pinnae and 



