STEMONITIS 119 



stems of Acer saccJiarinum Linn., and it appears to be widely 

 distributed. 



New England to Iowa, South Dakota, Washington, and Brit- 

 ish America. 



The plasmodium is white on maple stems, more creamy on 

 stems of linden, on which wood it is more rarely found. 



7. STEMONITIS FENESTRATA Rex. 



1890. Stemonitis bauerlinii f. fenestrata Rex, Proc. Phil. Acad., p. 36. 



Sporangia aggregated, in tufts an inch or more in diameter, 

 rich purple brown, on a common hypothallus, more or less erect, 

 stipitate, tall, about 2 cm., slender, triangular in section ; stipe 

 black, about one-third the total height, passing into a slender 

 columella which is lateral in position, not central, but little 

 branched, continued almost to the apex ; the capillitium con- 

 sisting almost entirely of the peripheral net, which presents 

 meshes of unusual uniformity of size and shape ; spores in mass 

 brown, colorless by transmitted light, nearly smooth, 6-7.5 A 1 - 



The remarkable shape of the sporangium and the peculiar 

 regularity of the surface net, the lateral columella, all combine 

 here to warrant the erection of a distinct species. Dr. Rex 

 referred this to 5. banerlinii Mass., at that time an unquestioned 

 species. Mr. Lister has since mixed this with 5. splendens, so 

 that there is nothing for us to do but record the American form, 

 which certainly bears no resemblance to European specimens 

 of 5. splendens. The resemblance, as pointed out by Dr. Rex, 

 lies with vS. morgani. 



The long, slender, simple columella is not only lateral, but 

 occupies indeed the sharp vertical angle of the triangular, pris- 

 matic sporangium. Furthermore, the sporangium is at maturity 

 strangely twisted, so that the columella in its ascent accom- 

 plishes one or more spiral turns. In forms collected by Dr. Rex, 

 which seemed to him most nearly to agree with Massee's spe- 

 cies, the inner capillitium is more abundant, but the character 

 of the columella just the same. 



Fairmount Park, Pennsylvania. 



