REPORT OF THE STATE BOTANIST. 43 
its being mistaken for or confused with any deleterious or poisonous 
species. 
The pileus is nearly always regular in shape, rather thick and mod- 
erately firm, hemispherical or convex when young but usually becom- 
ing more flattened or nearly plane with age. 
In its young state it is adorned with fine silky or hairy fibrils which 
sometimes, with advancing age, form minute persistent tufts or scales 
and sometimes disappear altogether, leaving the surface quite smooth. 
The decurved margin usually extends a little beyond the extremity of 
the lamellz. The cuticle or skin is more or less readily separable from 
the flesh, which is white, but sometimes manifests a tendency to 
change color slightly when cut or bruised, and to exhibit pinkish or 
reddish stains. The color of the pileusin the wild form is usually 
white or whitish with us, but in the cultivated forms it is often ochrey- 
brown or pale tawny, and varieties sometimes occur in which it is 
brown. 
The lamelle have a very beautiful and delicate pinkish hue which 
is apparent as soon as they are exposed to the light by the separation 
of the concealing veil from the margin of thepileus. This color grad- 
ually becomes darker with advancing age until it finally changes to a 
dark brown or almost black hue. This character 1s one of the best by 
which to distinguish the ‘‘ edible mushroom ” from all other Agarics, 
except its nearestallies, A. Rodmani and A. arvensis. And even from 
these, when young, it may readily be distinguished by the primary 
color of its lamellae. The subgenera Annularia and Pluteusin the 
pink-spore series contain species the lamelle of which exhibit similar 
pinkish colors, but these never change to brown or blackish-brown as 
the plant matures or becomes old. In the mushroom the lamelle are 
rounded at their inner extremity and not attached to the stem, so that 
generally in mature specimens there is a small free space between it 
and them. 
The stem is commonly short in proportion to the breadth of the 
pileus, its length being, in most cases, less than the horizontal diame- 
ter of the pileus. Ordinarily it is cylindrical in shape, though now 
and then instances occur in which it may either be slightly thickened 
or slightly narrowed toward the base. The central portion of the stem 
is a little softer in texture than the external portion, hence it is said — 
to be stuffed. The annulus encircles it at or near the middle. It is 
sometimes quite thin and flabby and is then easily torn and destroyed. 
The mushroom, like many other plants which have been the sub- 
ject of long and extensive cultivation, has given rise to several forms 
which exhibit quite marked distinctive features. These forms differ 
