1913] BRIEFER ARTICLES 401 
and with only the briefest comment to S. fusca, seems to warrant some 
further elucidation. Judging by the type specimen only, a portion of 
which was sent to me some years ago by the late Dr. REx, one would 
be justified in according to his species at least varietal rank. The 
strikingly dark color, the stiff, upright habit of the sporangia, not 
curved or drooping even at the edges of the clusters, and their small size 
(stalk less than 1 mm., total height 4.5 mm. or less) are features which 
appear to render this form recognizable at sight. Moreover, many 
gatherings made during the past ten years in as widely separated locali- 
ties as New England and Colorado show that this dark, dwarf form is 
fairly common in the United States. It should be noted also that with 
the distinct external features noted above certain microscopic features 
are usually associated, such as a more or less imperfect development 
of the surface net, the meshes of which show spinelike processes, and 
reticulated spores of a smoky-brown color. 
A number of gatherings made in Colorado, however, throw light 
on the variable character of S. nigrescens. Seven such gatherings 
are before me. They all agree in the short-stalked, upright, dwarf 
habit, and in the reticulated spores. But the color of the clusters 
of sporangia varies markedly from dull ferruginous to almost black; 
the surface net in one of the specimens is as perfectly developed and 
as free from spinous processes as in any typical specimen of S. fusca; 
while the spores vary in color from pale to dark smoky-brown, the former 
showing a very faint and delicate reticulation which is much more pro- 
nounced in the case of the darker-spored specimens. I cannot but 
conclude that these are all forms of one and the same species, and that 
they should be regarded as a dwarf variety of Stemonitis fusca Roth. 
This opinion is strengthened by the examination of a specimen 
collected at Pagosa Springs, Colorado, in August 1911. It shows the 
same dense clusters of stiff, upright, dark smoky-brown sporangia, 
short-stalked, and measuring less than 4mm. in height. The small- 
meshed surface net shows a few small spines. The spores, 8.9 in 
diameter, are rather dark in color, but instead of being reticulated 
they are closely and minutely spinulose. In my opinion this is a dwarf 
form of Stemonitis herbatica Peck, and bears the same relationship 
precisely to that species as do the dwarf forms commented on above 
to S. fusca. I conclude, therefore, that the Listers were correct in 
merging S. nigrescens Rex with S. fusca Roth, but that the former 
constitutes a well marked variety, though ill-defined by the designa- 
tion nigrescens—W. C. Sturcis, Colorado Springs, Colorado. 
