The Common Oyster is a decomposer and nematode hunter that can be found in the fall through the early summer. It grows on deciduous (and sometimes coniferous) dead wood and is widely distributed.

The top-view of the cap is circular, half-circular, fan-shaped, oyster-shaped to kidney shaped. The side-view of the cap is evenly rounded to flat, with an occasional central depression. The cap surface color is dark gray to tan to whitish. The white form can sometimes look similar to the closely related Pale Oyster. The featured specimens are among those that are confusing to separate.

The stem is usually quite sort or absent, but most often absent. Its attachment to the cap is variable, sometimes central bottom, off to the side on the bottom, or attached to the side of the cap (central, eccentric, or lateral, respectively). The gills run down the stem (decurrent). The pictured specimens don't have a stem.

Along with decomposing dead wood, this mushroom is interesting because it hunts for nematodes. It creates tiny loops of mycelium that it uses to trap the microscopic worm-shaped organisms in a grip of death. Please enjoy the video below describing the phenomenon in detail.

July 17th, 2023 Field Notes - Indian Cave State Park

• Growing on cut end of Bitternut Hickory log in low moist mixed oak/hickory woodland near small creek.
• Smell: mildly anise.

October 24th, 2023 Field Notes - Indian Cave State Park

Habitat:

• Growth Habit: Connate
• Substrate: Lignicolous
• Tree: Carya ovata

Attachment: Eccentric

Pileus:

• Shape:
  • Top view: Conchate
  • Profile: Convex to Plane
• Surface:
  • Texture: Smooth to Rimose [1]
  • Color: Buff to Cinnamon-Buff to Cream to Buff-Yellow

[1] Rimose towards margin.