This section is from the book "Our Edible Toadstools and Mushrooms and How to Distinguish Them", by W. Hamilton Gibson. Also available from Amazon: Our Edible Toadstools And Mushrooms And How To Distinguish Them.
In frequent company with the foregoing will be found another allied species, Coprinus atramentarius (Plate 17), with the same inky propensities, which is scarcely less delicious as an article of food. In this species the shaggy feature is absent, there being merely a few obscure slightly raised stains at the summit, of a brownish color. The stem is white and hollow. The surface of the pileus is smooth and of a Quaker-drab color, occasionally dirty-white, or with a slight shade of ochre, moist to the touch, darkened by rubbing. In the eatable stage the caps are drooping, as shown in the cluster on the plate, while the mature specimen expands considerably before its inky deliquescence. Its texture when young is firm, and the thick gray cuticle peels readily, leaving an appetizing nutty-flavored morsel, delicious even when raw. The inky Agaric is frequent about barn-yards, gardens, and old stumps in woods, and usually grows in such crowded masses that the central individuals are compressed into hexagonal shape. Like the previous variety, it should be collected for food while its gills are in the white or pink stage.
Cordier claims that all the species of Coprinus are eatable at this stage. The profusion in which they occasionally abound renders it often a simple matter to obtain a bushel of them in a few minutes.
Pileus: Fleshy, moist; at first egg-shaped; of a Quaker-drab, dirty white, or even pale brownish color; at length becoming expanded, umbrella-like, when it melts away in inky drops.
Gills: Broad and crowded, not adhering to stem at top; creamy white in young species, becoming pinkish gray, and at length black.
Stem: Firm; white; hollow.
Spores: Black; shed in liquid drops.
Taste: Sweet, as is also the odor, which applies to its early stage only.
Habitat: About old decaying stumps and rotten wood, gardens, rich lawns, and barn-yards; usually growing in clusters, often very dense.
Diameter of pileus, young state, two inches.
Plate XVII. Coprinus Atramentarius.
Like the foregoing, a large cluster of these mushrooms leaves a most unsightly spot on the lawn. A diluted solution of this melting substance, as Cooke assures us, has been used "to replenish the ink-bottle. The resemblance is so complete that it may readily be employed as a substitute, all that is required being to boil and strain it, and add a small quantity of corrosive sublimate to prevent its turning mouldy." It may also be employed as pigment. It is, indeed, quite possible to paint the portrait of Coprinus with its own dark sepia, as the author has personally demonstrated. (See head-piece to "Illustrations.")