Hygrophorus occidentalis

What You Should Know

Hygrophorus occidentalis is a species of Fungi in the family Hygrophoraceae. It appears white when in the button stage, but soon begins to develop grayish brown colors in the center of the cap, and by maturity, the cap may be brownish or grayish brown overall - except for the margin, which usually remains paler. It lacks a distinctive odor, and its cap and stem are slimy; these features help distinguish it from some of the other brownish waxy caps. The stem apex is punctuated with tiny white tufts of fibers, but the lower stem lacks the brown-fibrillose "inner veil" found in species like Hygrophorus olivaceoalbus.

Dried specimens change the color of the cap, gills, and stem to brown.

Hygrophorus occidentalis Mushroom Identification

1. Ecology

   Mycorrhizal with oaks and other hardwoods; growing scattered to gregariously; fall and early winter (and overwinter in warm climates); reported as widely distributed in North America, but see the note below about western collections.

2. Cap

   1-7 cm; convex with an inrolled margin when young, becoming broadly convex or flat; slimy; bald; white to very pale grayish at first, but soon developing gray to brown shades over the center; eventually grayish brown, with the margin typically remaining pale.

3. Gills

   Broadly attached to the stem or beginning to run down it; distant or close; white; short-gills frequent.

4. Stem

   2-6 cm long; 3-15 mm thick; equal above, but tapering at the base; slimy, at least over the lower portion; with tiny tufts of white fibers over the dry apex; white or becoming tinged with the cap color; sometimes staining yellowish at the base.

5. Flesh

   White; unchanging when sliced.

6. Odor and Taste

   Not distinctive.

7. Chemical Reactions

   KOH golden orange on cap surface (sometimes slowly).

8. Spore Print

   White.

9. Microscopic Features

   Spores 6.5-9 x 3.5-5 µ; smooth; ellipsoid; hyaline in KOH; inamyloid. Basidia 2- and 4-sterigmate; 35-42 µ long. Hymenial cystidia absent. Lamellar trama divergent. Pileipellis an ixocutis.

Sources:

Photo 1 - Author: aarongunnar (Attribution 4.0 International)

Photo 2 - Author: aarongunnar (Attribution 4.0 International)

Photo 3 - Author: gcsnelling (Attribution 4.0 International)