Lactarius chrysorrheus
Description
Lactarius chrysorrheus (sometimes spelled Lactarius Chrysorheus) is small to medium in size, has a cream to pale yellow- viscid cap, that is somewhat zoned with watery orange-cinnamon spots especially in the shallowly depressed central disc. The gills are cream-colored. White flesh. The stem is off-white-pinkish and dry. Slowly acrid white latex immediately turns bright sulfur yellow on contact with air. Pale yellow spores. Habitat under oaks in late summer and autumn.
Similar to Lactarius Vinaceorufescens, which is associated with conifers.
This mushroom contains toxins and is considered poisonous (although it has sometimes been listed as edible). Consumption of several species of poisonous milkcaps results in predominantly acute gastrointestinal symptoms, which can be severe.
Common names: Yellowdrop Milkcap.
Mushroom Identification
Ecology
Mycorrhizal with oaks and possibly other hardwoods; summer and fall; probably to be expected throughout the oak forests of eastern North America.
Cap
3-10 cm; broadly convex with an inrolled margin when young; becoming shallowly depressed or vase-shaped with an uplifted margin; moist or dry; smooth or finely roughened; pale pinkish to pale cinnamon; often with vague concentric zones of color, at least when young.
Gills
Attached to the stem or beginning to run down it; close; whitish to pale yellowish; not bruising or discoloring, not developing reddish spots with maturity.
Stem
3-8 cm long; 1-2 cm thick; more or less equal; dry; without potholes; whitish.
Flesh
White; firm; yellow when sliced.
Milk
Copious; white, becoming quickly yellow on exposure to air.
Odor and Taste
Odor not distinctive; taste acrid.
Spore Print
Yellowish.
Chemical Reactions
KOH on cap surface yellowish to pale olive.
Microscopic Features
Spores 6-9 x 5.5-6.5 µ; broadly ellipsoid; ornamentation 0.5-1.0 µ high, as amyloid warts and ridges that form partial reticula. Pleuromacrocystidia to about 75 µ long; fusiform. Cheilomacrocystidia similar. Pileipellis an ixocutis.
Similar Species
Lactarius quietus is of similar size and also occurs under oaks, but its latex is creamy white and does not turn yellow on exposure to air.
History
This mushroom was described in 1838 by the great Swedish mycologist Elias Magnus Fries, who gave it the binomial scientific name Lactarius chrysorrheus, which is still the name by which it is generally known today.
Lactarius chrysorrheus has a few synonyms including Agaricus theiogalus, Lactarius theiogalus, and Lactarius theiogalus var. chrysorrheus Quél.
In some field guides the specific epithet is spelt chrysorheus (with just one ‘r’ before the second 'h' ).
The generic name Lactarius means producing milk (lactating) - a reference to the milky latex that is exuded from the gills of milkcap fungi when they are cut or torn. The specific epithet chrysorrheus comes from the ancient Greek words chryso- meaning golden, and -rheos meaning stream. A stream of golden latex does indeed flow from the cut gills of these lovely woodland mushrooms.
In bright sunlight latex droplets of the Lactarius chrysorrheus shine like bright yellow stars and can often be seen at a distance of several metres.
Photo sources:
Photo 1 - Author: Richard Daniel (RichardDaniel) (CC BY-SA 3.0)
Photo 2 - Author: Strobilomyces (CC BY-SA 3.0)
Photo 3 - Author: Jimmie Veitch (jimmiev) (CC BY-SA 3.0)
Photo 4 - Author: A.Aguilera (CC BY-SA 4.0)
