also species with peculiar rings which we know in no other 
genus. In the young plant of Psalliota placomyces a section 
through the veil is wedge shape. It hangs by its thin edge 
from near the top of the stipe, the lower thick end being 
attached to the margin of the young pileus. As the pileus 
expands, it tears and splits this wedge-shaped veil so that 
the ring formed from it has the appearance of a double 
membrane, hence the “duplicatus annulus” of Fries. Our 
photograph however, (distributed as No. 50) which we 
select to show this feature, is better as an illustration than 
the word explanation. 
I believe the character of the ring, if correctly observed 
and recorded, would be a good natural feature by which to 
subdivide the genus which is one of the few genera Fries 
did not subdivide on natural relationship. 
H abitat. —All of our native species are terrestrial. Of 
the species I have met, campestris and its variety grow in 
manured ground and pastures, the remainder in the woods. 
Placomyces I have usually found in lawns and woodland 
pastures, but also in the woods. 
Literature. —Stevenson, page 304; Pries' Epic., page 
278; Peck, New York Species, 36th Rep., page 41; Peck 
Edible Species, 48th Rep., page 133 and plates 6, 7, 8 and 
9; Smith C. O. Species of Champlain Valley, Rhodora, 
September, 1899. 
51—PSALLIOTA CAMPESTRIS. 
Pileus convex-expanded, white or whitish, appressed 
even silky when young, breaking into fibrillose scales when 
old. Gills broad, free, pink when young, becoming dark 
brown, almost black when old. Stem short, equal, stuffed, 
white. Ring near the middle, small, often torn or disap¬ 
pearing. 
The above description is made from the wild plant as it occurs toler¬ 
ably constant in characters with us. The plant is extremely variable, espec¬ 
ially in cultivation, and numerous varieties are named as having pilei brown, 
reddish, scaly, etc. We received plants from Mrs. Langenbeck which were 
pure white and smooth. Psalliota campestris, better known perhaps as Agari- 
cus campestris, is the celebrated “edible mushroom” gathered in the fields 
and pastures in the fall of the year. It is the only species which, to our 
knowledge, can be successfully cultivated and is raised in considerable quan¬ 
tities by gardeners in the vicinity of all large cities. The cultivated plant, as 
we notice it in market, is covered with brown scales and is a much darker 
colored plant than the wild species around Cincinnati. A practicable 
method of cultivation is explained in detail in Farmers’ Bulletin No. 53. It 
