Lactarius olympianus

[ Basidiomycetes > Russulales > Russulaceae > Lactarius . . . ]

by Michael Kuo

Here is a gorgeous western milky cap recognized by a combination of features:

• a fairly large, bright orange cap with concentric zones of color;
• growth under mountain conifers;
• white milk that stains the gills brown or orangish brown;
• a stem that lacks potholes and discolors brownish when handled;
• acrid taste;
• a cap margin that is not hairy, even when young; and
• large, partially reticulate spores measuring 7-13 x 7.5-11 µ.

Lactarius olympianus is reminiscent of several other species in the "Lactarius zonarius" group, including the eastern, hardwood-associated Lactarius psammicola and the European species Lactarius zonarioides.

I have no information on the edibility of Lactarius olympianus; do not experiment.

Description:

Ecology: Mycorrhizal with high-elevation conifers (principally with spruces); summer and fall; Colorado to the Pacific Northwest.

Cap: 6-14 cm; convex with an incurved margin when young, becoming flat, shallowly depressed, or shallowly vase-shaped; slimy to sticky when wet; fairly smooth; the margin not hairy, even when young; bright orange with concentric zones of paler orange.

Gills: Attached to the stem or running down it; close or nearly distant; whitish at first, becoming yellowish or orangish; developing orangish brown to brown stains and discolorations.

Stem: 4-6 cm long; up to 3 cm thick; more or less equal, or with a tapered base; dry or moist; without potholes; smooth; whitish; discoloring brownish to dingy yellowish where handled.

Flesh: White; not changing when sliced, or developing rusty stains.

Milk: White; not changing when exposed to air; staining the gills brownish to orangish brown.

Odor and Taste: Odor not distinctive; taste usually acrid.

Spore Print: Creamy.

Microscopic Features: Spores 7-13 x 7.5-11 µ; broadly elliptical; ornamentation with prominences up to 1.5 µ high; connecting lines sometimes forming a partial reticulum.

REFERENCES: Hesler & Smith, 1979. (Hesler & Smith, 1979; Smith, Smith & Weber, 1979; Phillips, 1991/2005; Evenson, 1997; Leuthy, 1997.)

Further Online Information:

Lactarius olympianus in Hesler & Smith (1979)
Lactarius olympianus at Roger's Mushrooms

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Cite this page as:

Kuo, M. (2007, September). Lactarius olympianus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/lactarius_olympianus.html