THE RUSSULAS OF MADISON AND VICINITY. 
H. R. DENNISTON. 
The genus Kussula is well represented in Wisconsin, several 
species being extremely abundant. They grow on the ground 
and prefer a rich hilly woods where there is considerable moist¬ 
ure, but certain species are also found in low woods or open 
meadows. 
An unusually rich harvest of Russulas was gathered in the 
summer of 1903, when there was an abundant rainfall through¬ 
out the season. It was noted that in such a favorable season the 
bulk of the Russulas came in the latter part of July and the first 
part of August; after that, although large numbers of fungi were 
found, the Russulas were comparatively scarce, and other genera, 
especially the Cortinarii and Tricholomas, became relatively 
more abundant. 
The Russulas are easily distinguishable by their bright colors, 
brittle, white or cream colored gills and fleshy stem, but within 
the genus, a number of species are particularly difficult to sepa¬ 
rate. 
This difficulty is due largely to their extreme variability. If 
our common R. Integra is taken as an example, it is found that 
the color of the pileus may be purple, livid, greenish, brown or 
tawny. All of these colors may be present in the same indi¬ 
vidual and are often found in specimens growing in the same 
neighborhood. This variability of color is a feature of a num¬ 
ber of the commoner species of Russula, but not of all of them. 
The shape of the pileus usually changes as the plant grows 
older. On this account it is quite necessary to note the age of 
the specimen at which it has a certain form. In young plants 
