A description of the typical A. mellea will rarely apply to any one plant. A combination of its variable features in one description would include something of nearly every white-spored Agaric under the sun. Yet there is something indescribable about it which once learned will unerringly betray it.
Its Caps vary from perfectly smooth, through tufts of scales and hairs, more or less dense, to matted woolliness. It may show any one of these conditions in youth and be bald in age. Some shade of yellow is the prevailing color, but this will vary from whitish to dark-purplish or reddish-brown. When water-soaked it is one color, when dry, another. Commonly the margins of the Caps are striated, sometimes they are smooth as a cymbal, and not unlike one, have a raised place or umbo in the center. Flesh white or whitish. Gills when young are white or creamy, usually running down the stem, sometimes slightly notched at attachment. They freckle in age and lose their fair complexion. The Veil or collar about the stem is as variable as fashion—thick and closely woven or flimsy as gossamer, or vanishing as the plant grows old. The Stems may be even as a lead pencil, or swollen like a pen-holder, or bulbous toward the base, or distorted by pressure in the tufts. It is as variable in color as the cap, usually darkening downward in hues of brown. The outside is firm and fibrous, sometimes furrowed, inside soft or hollow.
Cap 1–6 in. across. Stem 1–6 in. long, ¼-¾ in. thick.
Var. obscu´ra has the cap covered with numerous small blackish scales.
Var. fla´va has the cap yellow or reddish-yellow, but in other respects it is like the type.
Var. gla´bra has the cap smooth, otherwise like the type.
Var. radica´ta has a tapering, root-like prolongation of the stem, which penetrates the earth deeply.
Var. bulbo´sa has a distinctly bulbous base to the stem, and in this respect is the reverse of var. radicata.
Professor Peck writes: “Var. exannulata (Plate [XVI], fig. 2, p. 52) has the cap smooth and even on the margin, and the stem tapering at the base. The annulus is very slight and evanescent or wholly wanting. The cap is usually about an inch broad, or a little more, and the plants grow in clusters, which sometimes contain forty or fifty individuals. It is more common farther south than it is in our state (N.Y.), and is reported to be the most common form in Maryland. This I call var. exannulata.” From Dr. Taylor, Washington, D.C.; Indiana, H.I. Miller.
To these may be added also var. al´bida Pk. in which the pileus is white or whitish.