Russula emetica

Common Name: None.
Description: Cap 5-10 cm across, convex, margin sulcate; bright scarlet red, cherry, or blood red; peels easily. Stem 50-100 by 10-25 mm high and wide.
Habitat: in swampy conifer woods. Found in northern North America.
Edible: Not edible.

Source: Mushrooms of North America by Roger Phillips.