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.
What a mass of nutritious food do we occasionally pass in innocence or spurn with our foot upon the old stump or fallen log in the woods! - a neglected feast, indeed, if the specialists on edible fungi are to be believed; a feast, in truth, for a big family, if we chance upon even an average cluster of the "vegetable oyster," which is pictured in Plate 14.
I have commonly observed this species, the Agari-cus ostreatus, in the autumn, and this is the season given for its appearance in Europe by the authorities; but according to certain American specialists, notably Charles Mcllvaine, it is common in our woods in spring, even as early as March, and through the summer. It is usually found in large clusters, similar to our illustration, growing upon decaying stumps and the trunks of various trees. The "oyster" is a gilled mushroom which grows sidewise from its position, the stem being usually lateral and very short, though occasionally quite prolonged, the two varieties being indicated in the accompanying cut.
A "vegetable oyster"
Agaricus Ostreatus - Variations In Form
The individual mushroom may be five or six inches in breadth, a cluster affording several pounds in weight. The color of the upper surface is light brown or buff, varying to yellowish-ashen, according to age, and the gills are dirty white of various lengths; spores white.
This species and the one following belong to the subdivision of the typical genus Agaricus, called Leucospori - white spored. The division has many sub-genera. The particular sub-genus in which these are included is the Pleurotus, or side-foot mushrooms, as they are sometimes called.
Pileus: Four to six inches in diameter; smooth. Color, dull, light yellowish, sometimes pale ochre or grayish. Gills: Dingy white; of various lengths, extending down the stem. Stem: Short or obsolete; on the side of pileus. Spores: White. Taste: Agreeable; suggesting the flavor of the cooked oyster; texture tough in older specimens. Odor: Pleasant. Habitat: On old tree trunks and fallen logs, occasionally in dense masses.
Plate XIV. Agaricus Ostreatus.
Another earlier species with which Agaricus ostreatus might be confounded (a. euosmus) has spores of a rosy pinkish or lilac hue, a sufficient identification, and is accounted injurious.
Thirty Pounds Of Vegetable Meat
The clustering growth of the "Oyster Mushroom" frequently attains huge proportions, as will be seen from the above reproduction of a photograph sent to me by a correspondent. The dimensions of the mass are easily judged by the height of the gun leaning against the tree, and introduced for comparison.
This "Oyster Mushroom" should be gathered in its young state, and may be served in various ways. Broiling over the coals, gills upward, seasoning with butter, pepper, and salt during the cooking, is a favorite method with most of the Agarics, but a well-known fungus epicure claims that this mushroom "may be cooked in any way that an oyster is, and will be found fine eating."
The average specimen will probably prove more ashen in hue than those represented in my plate.