Hygrophorus olivaceoalbus: The Ultimate Mushroom Guide
About The Hygrophorus olivaceoalbus Mushroom
Hygrophorus olivaceoalbus can be distinguished by its viscid brown cap, white gills, viscid white stipe ornamented with grey, greyish brown, to black fibrils, and growth with Sitka spruce. The fruit bodies appear from midsummer to late autumn under conifers in North American and Eurasian mountain forests.
Other characteristic features include a slimy stem up to 12 cm (4+3⁄4 in) long that is spotted with ragged scales up to a ring-like zone. As its name implies, the mushroom has a waxy cap and gills.
Other names: Olive Wax Cap.
Hygrophorus olivaceoalbus Identification
Traditionally thought to be mycorrhizal with conifers, but possibly parasitic on the roots of spruces and other conifers; often found under redwood and Sitka spruce on the West Coast, Engelmann spruce in the Rocky Mountains, and spruces or eastern hemlock in the northeast; growing scattered, gregariously, or in small clusters; late summer and fall (overwinter in warmer climates); fairly widely distributed in northern and western North America.
3-12 cm; convex when young, becoming broadly convex or more or less flat; sticky when fresh; with a streaked appearance from stretched-out fibers beneath the slime; dark brown to gray-brown; lighter towards the margin; the margin somewhat inrolled when young.
Attached to the stem or running down it; distant or nearly so; white; waxy; short-gills frequent.
3-10 cm long; up to 1 cm thick; equal or with a somewhat tapered apex; when fresh sheathed with slime over the lower portion; white at the apex; covered below the slime with brown fibers that stretch out as the mushroom grows and often become disposed as vaguely concentric stripes or bands by maturity; often with a fragile and imperfect or somewhat gelatinized ring; basal mycelium white.
Odor and Taste
KOH negative on cap surface.
Spores 8-13 x 4.5-6 µ; ellipsoid; hyaline in KOH; inamyloid. Basidia 4-sterigmate; to about 55 µ long. Hymenial cystidia absent. Lamellar trama divergent. Pileipellis an ixocutis with clamp connections present.
Hygrophorus olivaceoalbus Look-Alikes
Very similar species that associates with broad-leaved trees in Europe; it has been reported from California, but under spruce.
A smaller species with dry stipe is fairly common in Idaho and the Rockies.
Hygrophorus olivaceoalbus Taxonomy & Etymology
The species was first officially described as Agaricus olivaceoalbus by Elias Fries in 1815. It had earlier been published as Agaricus adustus by August Johann Georg Karl Batsch in 1783, but this was an illegitimate renaming of Agaricus brunneus published in 1774 by Jacob Christian Schäffer. It received its current scientific name when Fries transferred it to the genus Hygrophorus in 1838. Paul Kummer moved the species to Limacium in 1871, but this genus has since been sunk into synonymy with Hygrophorus.
Together with H. pustulatus, H. persoonii, H. mesotephrus and H. latitabundus, H. olivaceoalbus form the section Olivaceoumbrini within the genus Hygrophorus. The fungi of this section have greasy to slimy caps and stems. Their caps are darkish brown grey, olive or orange, and their stems are nattered or somewhat distinctly ringed.
Common names that have been used for the mushroom include the "slimy-sheathed waxy cap", the "olive hygrophorus", the "sheated waxgill" and the "olive wax cap".
The specific epithet olivaceoalbus is derived from the Latin words for olive-brown (olivaceus) and white (albus).
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