Central Florida, so probably not oyster. Also, definitely not an oyster based on that stem. And it was only an inch and half tall.
Oysters grow out of wood, for the most part. And you can see how it has gills instead of ridges. Ridges would gradually get narrower and less deep as they go down the stem. There is no sudden cut off between ridges and stem like there is between gills and stem.
There are better ways of identifying mushrooms than that, but that requires some books.