Common Edible Mushrooms

Purple or Purple-Brown Spore Print
GENUS Agaricus
The edible qualities of members of this genus were known to
the ancients, and it has the honor of being included in what was
probably the first cookbook in the English language, written
about 1390 by the chief cook of Richard II. One of the species
described below, Agaricus campestris, is the principal cultivated
mushroom of commerce. No one knows just when people
learned that these mushrooms could be grown artificially, but the
first record was made shortly after 1600, when the art was confined
to a comparatively small area near Paris. Before World
War I more than twenty miles of mushroom caves near Paris,
mostly in abandoned stone mines, supplied much of Europe with
fresh and canned mushrooms.
The "agarick" mentioned in some of the old herbals was not
Agaricus but a woody bracket growing on coniferous trees and
was erroneously supposed to be a specific cure for many of the
ills to which our failing flesh is heir.
The name Psalliota is a synonym of Agaricus and is preferred
by some botanists. It has the virtue of being more descriptive,
since it is taken from the Greek word psallion, meaning a ring
or collar, and refers to the ring surrounding the upper part of
the stem. Agaricus is derived from a Greek word meaning mushroom
and probably was merely one of several common terms
used for fleshy fungi in general.
The genus is characterized by (i) the deep purple-brown
spores, (2) the fleshy stem that can be separated easily from the
cap, (3) the definite ring on the stem seen when the cap expands
(this ring may wither and disappear later), and (4) gills free
from the stem.
The young gills of most species are white before the cap
opens, become pink as the spores begin to mature, and finally
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