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..
The genus Omphalia is closely related to Mycena and Collybia. It differs from these mainly in the decurrent gills. In the small species of Mycena where the gills are slightly decurrent, the pileus is not umbilicate as it is in corresponding species of Omphalia. In some of the species of Omphalia the pileus is not umbilicate, but here the gills are plainly decurrent. The stem is cartilaginous.
Plate 33, Figure 103
Omphalia campanella. Watkin's Glen, N. V., August, 1898. Caps dull reddish-yellow.
Gills yellow. Stem brownish, hairy at base. (Natural size.) Copyright.
One of the most common and widely distributed species of the genus is the little bell-omphalia, Omphalia campanella. It occurs throughout the summer and autumn on dead or rotten logs, stumps, branches, etc., in woods. It is often clustered, large numbers covering a considerable surface of the decaying log. It is 1-3 cm. high, the cap 8-20 mm. broad, and the stem very slender.
The pileus is convex, umbilicate, faintly striate, dull reddish yellow, in damp weather with a watery appearance. The gills are narrow, yellow, connected by veins, strongly curved because of the form of the pileus, and then being decurrent on the stem. The stem is slender, often ascending, brownish hairy toward the base, and paler above.
This plant occurs during the autumn in woods, growing usually on much decayed wood, or sometimes apparently on the ground. The smoky, or dull gray color of the entire plant, the depressed or funnel-shaped pileus, and short, slender stem serve to distinguish it. The cap is 2-4 cm. broad, the plant is 3-5 cm. high, and the stem 2-4 mm. in thickness.
The pileus is convex, becoming expanded, umbilicate or depressed at the center or nearly funnel-shaped, smooth, smoky or gray with a saturated watery appearance, light gray or nearly white when dry.
The gills are narrow, crowded, or a little decurrent. The slender stem is smooth, hollow, equal. Figure 104 is from plants (No. 3373, C. U. herbarium) collected in woods near Ithaca, N. Y., in the autumn of 1899.
Omphalia epichysium. Entire plant smoky or dull gray in color (natural size). Copyright.