Russula decolorans, also known as Copper Brittlegill, is a medium to large agaric that has a distinctively coloured, often brick-red cap, pale yellow gills and white stem. All parts of the mushroom are greying or blackening. The mushroom grows with conifers, often in bogs. It thrives solitarily, in scattered clusters, or sometimes in large groups during the summer and fall seasons.

Cap as young almost completely round, then convex to flat, often with a depressed center. At first bright orange-yellow, then more subdued brick-red, sometimes with a darker centre. Sticky in damp weather, and has smooth skin that can be removed, but not easily. The flesh is white, hard and staining slowly grey to black when sliced. Gills at first white, then creamy yellow and finally grey. Reaching but not attached to the stem. Stem is white, greying readily when bruised or with age, more or less equal or somewhat club-shaped, stout, and smooth. The stem has no ring. Spore print pale yellow.

Microscopic Features: The spores are elliptical in shape, measuring approximately 9-14 µ in length and 7-10 µ in width. They exhibit isolated warts, which can reach a height of up to 1.5 µ. Additionally, there are only a few connectors scattered throughout the spore surface.

Russula decolorans on the MushroomExpert.Com Web site.