_Agaricus campestris_
[Sidenote: ="The" mushroom=]
[Sidenote: =Description of Campestris=]
Perhaps the one species which enjoys the widest range of popular
confidence as the "mushroom" in the lay mind, as distinguished from
"toadstool," is the _Agaricus campestris_, known as the "meadow
mushroom" (Plate 5). It is the species commonly exposed in our markets.
Its cultivation is an important industry, but it often yields an
enormous spontaneous harvest in its native haunts. The plate shows a
cluster of the mushrooms in their various stages of development, the
detached specimen below representing the semi-opened condition in which
the fungus is usually gathered for market. It will be observed that
the base of the stem is _entirely free from any suggestion of a volva
or cup_. As its popular name implies, this species in its wild state
is one of the voluntary tributes of our late summer and autumn meadows
and pastures, though it may occasionally frequent lawns, shrubberies,
and barn-yards. In size it varies from two to three and a half inches
across the pileus or cap, which is either smooth or slightly rough,
scaly, or scurfy, and creamy white or tawny in color, according to age
or variety. The most important distinguishing feature of this species
is the color of the gills. If we break away the "veil" in the unopened
specimen, we find them to be of a pallid flesh tint. In the more
advanced state they become decidedly pinkish, with age and expansion
gradually deepening to purplish, purple-brown, and finally brownish
black. The gills are of unequal lengths, as shown in the section. The
stem is creamy white and of solid substance, and always shows the
remains of the veil in a persistent frill or ring just beneath the cap.
[Illustration: Agaricus campestris]
_PLATE V_
"THE MUSHROOM"
_Agaricus campestris_
=Pileus:= At first globular, its edge connected to
stem by the veil; then round convex, at length
becoming possibly almost flat. Surface dry, downy,
or even quite scaly, varying in color from creamy
white to light brown. Diameter at full expansion,
about three inches.
=Gills:= Unequal in length; pink when first revealed,
becoming brownish, brown, purplish, and finally
almost black.
=Stem:= Solid; of the color of the cap; paler and
white in section, retaining the remnant of the veil
in a permanent ragged ring.
=Spores:= Brown.
=Taste:= Sweet and inviting, and odor agreeable.
=Habitat:= Pastures, lawns, and open rich soil
generally.
=Season:= Late summer and early autumn, occasionally
in spring.
[Illustration: PLATE V AGARICUS CAMPESTRIS.]
[Sidenote: =Cultivation of mushrooms=]
Doubtless a sufficient and satisfactory reason for the universal
dignity which this species has acquired as "the mushroom" may be found
in the fact that it is the only species prominently under cultivation,
and almost the only one which is sure to respond to the artificial
cultivation of its spawn in the so-called "mushroom bed." The "spawn"
of the Campestris has thus become a mercantile commodity, duly
advertised in the seedsmen's catalogues.
[Sidenote: =Mushroom "spawn" bed=]
This so-called spawn is in truth nothing but the mycelium, or
subterranean vine of the mushroom (see Plate 2), taken from the beds
in which the mushrooms have been grown, or in which the mycelium has
been cultivated. The cultivator simply prepares a "bed" to receive
it--duplicating as far as possible the soil conditions from which it
was taken, whether from foreign cultivation or his old manure-bed or
stable-yard--a rich, warm compost of loam and horse-manure, this latter
ingredient being a most important consideration, as the fungus in its
several varieties, notably the larger, _Agaricus arvensis_, known as
the "horse-mushroom," has followed the track of the horse around
the world. These natural conditions having been even approximately
fulfilled, will, within two months, generally reward the cultivator
with a crop of mushrooms, which, with the continued ramifications of
the mycelium permeating the muck as the yeast fungus permeates the
home-made loaf, will insure a continual succession of crops for weeks
or months, to be renewed spontaneously, perhaps, the following season.
The present volume, having specific reference to fungi in their wild
state, and the celebration of their esculent virtues, being thus
essentially in antithesis to artificial culture, further consideration
of the cultivation of the mushroom is omitted. The reader is referred
to the volumes in my bibliographical list, Nos. 8 and 22, in which full
instructions will be found.
[Sidenote: =Species opposed to cultivation=]
[Sidenote: =Certain exceptions=]
The Campestris is conspicuous among mushrooms in its ready
accommodation to artificial imitation of its native environment. There
is no other mushroom which is thus confidently to be relied on. Other
species--not a dozen, however, out of the thousands--will occasionally
reward the cultivator, who has devoted the most scrupulous care to the
humoring of their fastidious conditions of growth. Thus the _Agaricus
candicans_ of the Italian markets is said to have been successfully
raised from chips of the white poplar which have been properly covered
with manure. Other species, it is claimed, can be humored from a block
of the cob-nut tree after singeing its surface over burned straw, while
Dr. Thore claims that both _Boletus edulis_, and _Agaricus procerus_
are "constantly raised by the inhabitants of his district from a watery
infusion of said plants poured upon the ground." The truth of these
statements has been denied by authorities, and individual experiment
will only tend to discredit their trustworthiness. In general the
mushroom or toadstool absolutely refuses to be "coaxed or cajoled."
The mycelium of all is practically identical; but species such as the
Coprinus, for instance, which are perhaps found growing naturally in
company with the Campestris, and whose spawn is similarly transplanted
to the artificial environment, will show no sign of reappearance, while
its fellow may literally crowd the bed.
[Sidenote: =Not to be humored=]
The "fairy-ring" mushroom grows year after year upon our lawn,
because its mycelium is continually present, simply threading its way
outwardly, inch by inch, in the congenial surrounding soil. Instances
are reported of the occasional successful establishment of this
mushroom in new quarters by the transfer of a clod of earth threaded
with mycelium taken from the "fairy-ring" to another lawn, in which the
immediate soil conditions happened to be harmonious, and this method
of actual transference of the spawn might occasionally be effectual.
But the writer, in his limited number of experiments, has never yet
been able to propagate a mushroom by a transfer of the _spores_ to soil
where the conditions would appear to be exactly suitable. On a certain
lawn, for instance, every year I obtain a number of the _Coprinus
comatus_ (Plate 16). Upon another lawn, apparently exactly similar
as to soil conditions, I transfer the melting mushroom where it
sheds its inky spore-solution upon the earth, and yet, after years of
waiting, there is no response. Even an absolute transfer of the webby
spawn from the original haunt has proven equally without result. Thus
while the habitual fungus-hunter comes to recognize a certain logical
association between a given character of natural haunt and some certain
species of fungi--a prophetic suspicion often immediately fulfilled--as
when he inwardly remarks, as he comes upon an open, clear spot in the
woods, "This is an ideal haunt for the green Russula," and instantly
stumbles upon his specimen; yet he may take the pallid spawn, with a
small clod of earth from its roots, and place it in the mould not ten
feet distant, apparently in identically auspicious conditions, and it
absolutely refuses to be humored. He may mark the spot, and look in
vain in its precincts for a decade for his Russula, though the ground
in the vicinity be dotted with them.
[Sidenote: =Dormant spores=]
Year after year I have thrown my refuse specimens of hundreds of
species of fungi out of my studio window, over the piazza rail or upon
my lawn, yet never with the slightest sign that one of the millions of
spores in the species thus sown has vegetated.
Considering the ready accommodation of the Campestris, the contrast
of the fastidiousness in other species is a notable phenomenon. As a
rule, "they will not colonize; they will not emigrate; they will not be
cheated out of their natural possessions: they refuse to be educated,
and stand themselves upon their single leg, as the most independent and
contrary growth with which man has to deal."
[Illustration: PLATE VI. VARIATIONS IN AGARICUS CAMPESTRIS]
[Sidenote: =Varieties of the Campestris=]
The Campestris is probably the most protean of all mushrooms, and
mycologists are even yet at odds as to the proper botanical disposition
of many of the contrasting varieties which it assumes. A few of these
are indicated in Plate 6. Indeed, some of these, as in the _Agaricus
arvensis_, following, have until quite recently figured as distinct
species. In its extreme form it might well so do, but when science
is confronted with an intermediate specimen bearing equal affinities
to the Campestris and Arvensis--and perhaps reinforced by other
individuals which actually merge completely into the Campestris--the
discrimination of the Arvensis as a distinct species becomes
impossible, and would hardly seem warrantable.
Berkeley gives the following selection of the more distinct varieties,
not including the Arvensis with _its_ variations, and which he
considers a distinct species:
1. The so-called "garden mushroom," with its brownish,
hairy, scaly cap.
2. _A. pratensis_, in which the pileus is more or less
covered with reddish scales, and the flesh as well as
gills a pinkish tinge.