Lactarius fuliginellus is a species of mushroom-forming fungus in the family Russulaceae. It was first scientifically described by mycologists L.R. Hesler and Alexander H. Smith in 1962. The species is classified within the genus Lactarius, commonly referred to as milk-caps, and is placed in the section Plinthogali, a group characterized by species whose flesh or latex stains pinkish to reddish when exposed to air.
Morphology
The cap of Lactarius fuliginellus typically measures between 3 and 7.5 centimeters in diameter. It is initially convex, often becoming flat or slightly depressed at the center as it matures. The surface is dry, lacks viscidity, and possesses a velvety or finely scurfy texture. Its coloration is generally dark, ranging from sooty-brown to olive-brown or smoky-gray.
The gills are white to cream-colored, closely spaced, and adnate or slightly decurrent. When bruised or cut, the gills stain a pinkish-cinnamon color. The stem is solid, measuring 4 to 10 centimeters in length and approximately 1 to 1.5 centimeters in thickness; it is usually concolorous with the cap or slightly paler.
Latex and Spores
Like other members of its genus, Lactarius fuliginellus produces a milky fluid known as latex. The latex is white but reacts with the mushroom's context (flesh) to produce a distinct reddish or salmon-pink stain upon exposure to oxygen. The spore print is yellowish-buff. Under microscopic examination, the spores are globose to subglobose, measuring 7–9 by 7–8 µm, and feature amyloid ornamentation consisting of ridges that form a partial or nearly complete reticulum.
Ecology and Distribution
Lactarius fuliginellus is an ectomycorrhizal fungus, forming a symbiotic relationship with the root systems of coniferous trees. It is most frequently associated with spruce (Picea) and fir (Abies). The species is native to North America, with documented occurrences primarily in the northeastern United States, the Great Lakes region, and adjacent areas of Canada. It typically fruits in moist, mossy coniferous or mixed forests during the late summer and autumn.
Edibility
Insufficient Encyclopedic Information. While some members of the genus Lactarius are edible, many species in the section Plinthogali are considered of unknown edibility or are avoided due to the lack of documented consumption history. Professional mycological sources do not recommend Lactarius fuliginellus for human consumption.