Late Oyster Mushroom

IUCN Red List

NatureServe

Minnesota

not listed

Widespread and common

October through December

Mostly dead hardwoods, especially cherry, but also dead conifers.

This is a common, widespread, small to medium-sized, fleshy, shelf-like fungus. It is saprobic on decaying stumps and logs. It is found singly or in overlapping groups on the trunk or a large branch of a dead and decaying tree. It usually occurs on a hardwood, especially black cherry, but occasionally also on a conifer. It appears in the late fall with the onset of cold weather.

There is often no stalk. If there is a stalk it is short, 3 ⁄16″ to ⅝″ long, thick, and laterally attached. It is yellow, brownish-white, or the same color as the cap, and is covered with velvety hairs.

The cap is kidney-shaped or semi-circular and 13 ⁄16″ to 4″ in diameter. The color is variable, often on the same cap. When young it is downy and often flushed with violet. As it ages it becomes hairless and olive-green to yellowish-green. Eventually it turns yellowish-olive or light brown. When wet it is somewhat slimy or sticky to the touch (viscid). The margin is rolled inward and often lobed, indented, or wavy. As it ages the margin flattens out. The flesh is thick, white, and firm, and there is a gelatinous layer just below the skin (cuticle) of the cap. It is edible but has a mediocre taste and becomes bitter as it ages.

There is no universal veil.

The gills are narrow, close together and run down the stalk if there is one (decurrent) or broadly attached (adnate). They are bright orangish-yellow, yellowish-orange with a brown tinge, pale orange, or pale yellow at first, fading with age.

The spore print is pale yellow.

Sources: 4, 7, 26, 29, 30, 77.

Taxonomy
This mushroom was formerly placed in the family Tricholomataceae and known as Sarcomyxa serotina. Tricholomataceae is a “wastebasket taxon” containing all mushrooms in the order Agaricales with white, yellow, or pink spores that have not already been classified into another family. Following a large-scale phylogenetic study of Agaricales (Moncalvo, Vilgalys, Redhead, et al., 2002), seven families, including Mycenaceae, have been segregated from Tricholomataceae. Most authorities, including Index Fungiforum, use the new classification. NCBI³⁴ continues to use the old classification.

Cap

Gills