Seemed to pop up overnight. Growing on exposed roots of an old hard maple.

Most likely oysters. A bit overripe if so and probably maggot-ridden. They should be okay to eat, but one can find better edible fungi in the woods right now. Oysters should have rudimental off-center stems more or less firmly attached to the wood, gills that run down the stem, and be sort of rubbery in texture.

For a good mushroom id, pictures of the lower surface and a couple of close-ups are very helpful.

There is a somewhat similar deadly poisonous Ivory Funnel mushroom, Clitocybe dealbata, which grows in grass or on bare soil, often in similar clusters, but it has a central stem, watery blotches on the cap and very brittle flesh (if you toss it against a wall, it will shatter into lots of small pieces). Unlike oyster mushrooms, which smell nice, the Ivory Funnel has a stale, mealy smell. It's not VERY similar, but when collecting oysters growing on roots, especially when there are many, it's important to check each cluster, because even a single Ivory Funnel can cause big problems. It's safer to collect oysters that grow on wood above ground if you are not sure about the id.

There are also similar saw-leaf mushrooms of the genus Lentinus, considered inedible but nontoxic, that also grow on wood and resemble oysters, but they have serrated gill edges, a musty, woody smell and are generally more rare.

I agree,,, they look like oysters

Break one off and lets see the stem and bottom.If oysters the gills will run the whole way down the stem.Don`t really look like oysters to me.

Another poisonous look alike:"Angels Wings": Pleurocybella Porrigens: Only grows on Conifer wood.Not on hardwood like the Oysters.I have always found the Oyster Mushrooms to have a slight Anise or black licorice smell.We harvest quite a few of them here.

Oysters should only grow off of wood, anything that grows out of the grass is not an oyster

Hard wood to be precise.Not conifers.

I found something like that once, but I thought they were called Bonnet mushrooms.

I have a patch at my house that grow on the tree (maple) and the ground in a ten foot circle around it