Cortinarius sanguineus, commonly called the Blood-red Webcap, is a small to medium-sized mushroom with a vivid crimson to dark blood-red cap, gills, and stem. It is most often found in coniferous forests, particularly among spruces and pines, and is well known as a traditional dye mushroom.

Cap small to medium, at first convex or bell-shaped, later broadly convex to almost flat, sometimes with a low umbo. The surface is dry, silky to finely fibrous, bright blood-red to dark crimson, often with radiating fibrils. The margin is not lined. The flesh is pale pinkish to purplish-red and does not change when cut. Gills broadly attached and fairly close, at first vivid blood-red, later turning cinnamon to rusty red as the spores mature. Short gills are frequent. In young specimens they are covered by a red cortina. Stem cylindrical and sometimes slightly swollen at the base, dry and silky, coloured like the cap or slightly paler towards the base, and may occasionally show a rusty ring zone. The basal mycelium is reddish. Spore print rusty brown.

Microscopic Features: Spores ellipsoidal with a rough surface, measuring 7–9 × 4–6 µm.

Cortinarius sanguineus on the First Nature Web site.
Cortinarius sanguineus on the MushroomExpert.Com Web site.