This section is from the book "Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc.", by George Francis Atkinson. Also available from Amazon: Studies of American Fungi: Mushrooms, Edible, Poisonous, Etc..
In the genus Pluteus the volva and annulus are both wanting, the gills are usually free from the stem, and the stem is easily broken out from the substance of the cap, reminding one in some cases of a ball and socket joint. The substance of the cap is thus said to be not continuous with that of the stem. The spores seen in mass are flesh colored as in other genera of this subdivision of the agarics.
Pluteus cervinus. Cap grayish brown, or sooty, smooth or sometimes scaly, rarely white, stem same color, but paler; gills first white, then flesh color (natural size, often larger). Copyright.
Pluteus cervinus Schaeff. Edible. - This is one of the very common species of the higher fungi, and is also very widely distributed. It varies considerably in size and appearance. It is 7-15 cm. high, the cap 5-10 cm. broad, and the stem 6-12 mm. in thickness. It occurs on the ground from underground roots or rotten wood, or grows on decaying stumps, logs, etc., from spring until late autumn. Sometimes it is found growing in sawdust.
The pileus is fleshy, bell-shaped, then convex, and becoming expanded, the surface usually smooth, but showing radiating fibrils, grayish brown, or sometimes sooty, sometimes more or less scaly. The gills are not crowded, broad, free from the stem, white, then becoming flesh color with the maturity of the spores. One very characteristic feature of the plant is the presence of cystidia in the hymenium on the gills. These are stout, colorless, elliptical, thick-walled, and terminate in two or three blunt, short prongs.
Pluteus tomentosulus. Cap and stem entirely white, gills flesh color, stem furrowed and tomentose (natural size). Copyright.
The stem is nearly equal, solid, the color much the same as that of the pileus, but often paler above, smooth or sometimes scaly.
In some forms the plant is entirely white, except the gills. In addition to the white forms occurring in the woods, I have found them in an old abandoned cement mine growing on wood props.
This plant was described by Peck in the 32d Report, N. Y. State Mus., page 28, 1879. It grows on decaying wood in the woods during July and August. The plants are 5-12 cm. high, the cap 3-7 cm. broad, and the stem 4-8 mm. in thickness. The description given by Peck is as follows : "Pileus thin, convex or expanded, subumbonate, dry, minutely squamulose-tomentose, white, sometimes pinkish on the margin; lamella' rather broad, rounded behind, free, crowded, white then flesh colored; stem equal, solid, striate, slightly pubescent or subtomentose, white; spores sub-globose, 7 µ in diameter, generally containing a large single nucleus." From the plant collected at Ithaca the following notes were made. The pileus and stem are entirely white, the gills flesh color. The pileus is expanded, umbonate, thin except at the umbo, minutely floccose squamulose, no pinkish tinge noted; the flesh is white, but on the umbo changing to flesh color where wounded. The gills are free, with a clear white space between stem and rounded edges, crowded, narrow (about 3-4 mm. broad) edge finely fimbriate, probably formed by numerous bottle-shaped cystidia on the edge, and which extend up a little distance on the side of the gills, but are not distributed in numbers over the surface of the gills; cystidia thin walled, hyaline. The spores are flesh colored, subglobose, 5-7 µ. Stem cylindrical, even, twisted somewhat, white, striate and minutely squamulose like the pileus, but with coarser scales, especially toward the base, solid, flesh white.
The species received its name from the tomentose, striate character of the stem. The plants (No. 3219, C. U. herbarium) illustrated in Fig. 136 were collected in Enfield Gorge, vicinity of Ithaca, July 28, 1899.