Cortinarius sanguineus is a species of mushroom belonging to the Cortinariaceae family. It is commonly found in coniferous and mixed forests, often growing in association with trees like pine and spruce. The mushroom features a reddish-brown cap that can be smooth or slightly sticky when wet, and its gills are closely spaced and can appear yellowish to rusty brown. This species is known for its distinctive coloration and is typically found in late summer to autumn. While it is not considered edible, it is important for maintaining forest ecosystems. Proper identification is crucial, as some Cortinarius species can be toxic.