Hygrophorus olivaceoalbus, also known as the Olive Wax Cap, is a medium-sized, distinctive species of waxcap mushroom that thrives in damp, coniferous forests, particularly among pine and spruce. It is easily identified by its slimy, olive-grey to olive-brown cap, which becomes more pronounced in wet conditions.

Cap convex, flat, or slightly concave at the centre, with a slimy texture. It is black or dark smoky olive at the centre, and streaked toward the margin with olive-grey to black fibrils. The flesh is thick and white. Gills either attached to the stem or run slightly down it, distant or nearly so. They are white, waxy in texture, and frequently feature short gills. Stem slimy in wet weather, often wavy or bent, and tend to be thinner at the apex. It is white at the apex and covered with brown fibres beneath the slime. As the mushroom grows, these fibres stretch out and often form faint concentric stripes or bands by the time it matures. It often has a fragile and imperfect or somewhat gelatinized ring. Spore print white.

Microscopic Features: The spores are 8-13 x 4.5-6 µ in size, ellipsoid in shape, hyaline in KOH, and inamyloid.

Hygrophorus olivaceoalbus on the MushroomExpert.Com Web site.
Hygrophorus olivaceoalbus on the mykoweb.com Web site.