Laccaria amethysteo-occidentalis is a mushroom found under conifers, usually pine, growing alone, scattered or gregariously in western North America.
The mushroom is entirely purple. The cap is in width; broad, convex to flat, often depressed, occasionally becoming slightly translucent-striated when fading, finely fibrillose, hygrophanous, fading to violet; margin rolled inward, later becoming flat; context thin and lighter grayish purple in color.
The gills are purple, thick and distant. The stem is up to long, fibrous, with a whitish mycelium near the base.
The spores are 7.5âÂÂ10.5 x 7âÂÂ16 üm, subglobose or broadly elliptical. The spore print is white.
Basidia are 34âÂÂ56.5 à9.7âÂÂ14.7 üm, clavate, elongate, hyaline. Pleurocystidia absent. Cheilocystidia are 36.5âÂÂ66.5 à12âÂÂ18.4 üm, subclavate to clavate, thin-walled, hyaline, often very abundant, extending well beyond basidia.
This species is similar to L. amethystina but differs by occurring in hardwood forest in eastern North America, rather than coniferous forest; having a smaller sporocarp; and being a lighter purple color. L. bicolor is smaller and less purplish; L. laccata has whitish mycelium at its base. Cortinarius violaceus is darker and has a less fibrillose stipe. Pseudoomphalina cokeri is also similar.
It can be found on the ground near the North American West Coast from October to February.
The mushroom is edible, with good texture, but not much flavor.