Black oyster mushrooms are a medium-to-large oyster variety growing in shelf-like structures, with caps averaging 5 to 25 centimeters in diameter and a very short or non-existent stem. The caps, when young, may appear smaller and more convex, growing larger, flatter, broader, and wavier over time. The caps also display a unique black and white marbling across the surface, and there are white gills underneath the cap, giving the mushrooms a meaty and firm consistency. The thick, white stems are also edible, not just the caps. Black oyster mushrooms have a slightly chewy texture and are soft, with a bittersweet aroma reminiscent of anise. They also have a mild, sweet, and nutty, umami-forward flavor.