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 is a pretty little species and usually occurs on much decayed wood, lying close to the ground so that it is usually directly on the under side of the log or branch. It does occur, however, on the side of the log when it is more or less shelving, because of the tendency of the pileus always to be more or less horizontal.
The pileus is 4-6 mm. broad, its upper surface closely applied to the wood or bark on which it is growing when it appears directly on the under side. The margin is sometimes free and involute. Sometimes it is attached only by the center of the pileus. There is then often a short process. When it grows on the side of the log it is attached laterally, or on the upper side of one margin, while the greater portion of the pileus is free and shelving. The surface is smooth or somewhat hairy. The color varies from gray to dark bluish gray, or black with a bluish tinge. The gills are thick, broad in proportion to the size of the cap, distant, and are said by some to be paler than the pileus. In plants collected at Ithaca, the gills are often as dark as the pileus. The entire plant is rather tough, and revives after being dried if placed in water, resembling in this respect Maras-mins. Partus, or Trogia, and it may be more nearly related to one of these. Figure 114 is from plants (No. 4599, C. U. herbarium) collected at Ithaca.
Pleurotus applicatus. Color gray to dark bluish gray, or black with a bluish tinge (natural size). Copyright.