Armillaria straminea (Krombh.) Kummer var. americana Mitchel & Smith Cap 4-18cm across, conical to convex, becoming umbonate then flat, with incurved, cottony margin that straightens in age; straw yellow fading to whitish with conspicuous, flattened, bright yellow or darker scales arranged in concentric circles; dry. Gills sinuate, close, broad; whitish then lemon yellow. Stem 50-125x 15-25mm, sometimes with a thick bulb; smooth and white above the ring, whitish with shaggy yellowish scales below. Veil partial veil leaving thick, yellowish, cottony ring on upper stalk. Taste mild. Spores ellipsoid, smooth, weakly amyloid, 6-8 x 4-5µ. Deposit white. Habitat on the ground under aspen and in mixed woods. Often abundant. Found in the Pacific Northwest and the Rockies. Season July-October. Edibility not known. Comment There is also an albino form of this species.