This species is distinguished from the S. semiglobata by the distinct pithy substance with which the stem is stuffed, also by the fact that the cap is never fully expanded. It is found on dung and manure piles, in richly manured fields, and sometimes in woods.
Æruginosa is from ærugo, verdigris. The pileus is fleshy, plano-convex, subumbonate, clothed with a green evanescent slime, becoming paler as the slime disappears.
The gills are firmly attached to the stem, soft, brown, tinged with purple, slightly ventricose, not crowded.
The stem is hollow, equal, fibrillose or squamose below the ring, tinged with blue.
This species is quite variable in form and color. The most typical forms are found in the fall, in very wet weather and in shady woods. This is one of the species from which the ban has not been removed but its appearance will lead no one to care to cultivate its acquaintance further than name it. It is claimed by most writers that it is poisonous. Found in meadows and woods, from July to November.
Hypholoma is from two Greek words, meaning a web and a fringe, referring to the web-like veil which frequently adheres to the margin of the cap, not forming a ring on the stem and not always apparent on old specimens.
The pileus is fleshy, margin at first incurved. The gills are attached to the stem, sometimes notched at the stem. The stem is fleshy, similar in substance to the cap.
They grow mostly in thick clusters on wood either above or under the ground. The spores are brown-purple, almost black.
This genus differs from the genus Agaricus from the fact that its gills are attached to the stem and its stem is destitute of a ring.
[Illustration: _By the courtesy of Captain McIlvaine._
Plate XXXVII. Figure 262.--Hypholoma incertum.]
Incertum, uncertain. Prof. Peck, who named this species, was uncertain whether it was not a form of H. candolleanum, to which it seemed to be very closely related; but as the gills of that plant are at first violaceous and of this one white at first, he concluded to risk the uncertainty on a new species.
The pileus is thin, ovate, broadly spreading, fragile, whitish, margin often wavy and often adorned with fragments of the woolly white veil, opaque when dry, transparent when moist.