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..
This rare species, first collected in the Catskill Mountains 1869, and described by Peck in the 23rd Report, N. Y. State Mus., p. 86, 1870, was found by me on two different occasions at Ithaca, N. Y., during the autumn of 1898, on rotting logs, Ithaca Flats, and again in Enfield Gorge, six miles from Ithaca. The plants are from 5-8 cm. high, the cap 3-5 cm. broad, and the stem 5-7 mm. in thickness, and the entire plant is of a dull, or pale, yellow.
The pileus is nearly regular, fleshy, thin toward the margin, convex, umbonate, smooth or with a few small scales. The gills are rather crowded, broad, rounded or notched at the stem, pale yellow. The spores are elliptical, 7-9 x 5-6 µ. The stem is ascending and curved, nearly or quite central in some specimens in its attachment to the pileus, whitish or yellowish, mealy or slightly tomentose at the apex.
Pleurotus sulfureoides. Entire plant dull or pale yellow (natural size). Copyright.
Figure 111 is from plants (No. 2953, C. U. herbarium) on rotting log, Ithaca Flats, October, 1898.
Pleurotus petaloides Bull. Edible. - The petal-like agaric is so called from the fancied resemblance of the plant to the petal of a flower. The plant usually grows in a nearly upright or more or less ascending position, or when it grows from the side of a trunk it is somewhat shelving. It is somewhat spathulate in form, i.e., broad at the free end and tapering downward into the short stem in a wedge-shaped manner, and varies from 2-10 cm. long and 1-5 cm. in breadth. It grows on fallen branches or trunks, on stumps, and often apparently from the ground, but in reality from underground roots or buried portions of decayed stumps, etc.
Pleurotus petaloides. Color pale reddish brown or brown sometimes entirely white; gills white (natural size). Copyright.
The pileus varies from a regular wedge-shape to spathu-late, or more or less irregularly petaloid, or conchoid forms, the extremes of size and form be-ing shown in Figs. 112, 113. The margin is at first involute, finally fully expanded, and the upper surface is nearly plane or somewhat depressed, The color is often a pale reddish brown, or brown, and sometimes pure white. The margin is sometimes marked with fine striations when moist. The upper portion near the union with the stem is sometimes tomentose, sometimes smooth. The gills are narrow, white, or yellowish, crowded and strongly decurrent. While the plant varies greatly in form and size, it is easily recognized by the presence of numerous short whitish cystidia in the hymenium, which bristle over the surface of the hymenium and under a pocket lens present a "fuzzy" appearance to the lamellae. They are 70-80 x 10-12 µ. The spores are white.
Pleurotus petaloides. More irregular form than that shown in figure 112; color same as there described (natural size). Copyright.
Figures 112, 113 are from plants collected at Ithaca.
Pleurotus serotinus Schrad. This is an interesting plant and occurs during the autumn on dead trunks, branches, etc., in the woods. The stem is wanting, and the cap is shelving, dimidiate, reniform or suborbicular. The plants occur singly or are clustered and overlapping, about the same size and position as Claudopus nid-ulans, from which it is readily told by its white gills and spores. The color varies from dull yellow to brownish, often with shades of olive or green.