Bearded Milkcap or Wooly Milkcap
Known for 250 years, this Lactarius officially became the type species for Lactarius in 2011. It has a widespread distribution in temperate and boreal and sometimes subarctic habitats around the northern hemisphere where it is found in mixed forests. It has a predilection for growing in mycorrhizal association with birch and hemlock species. It is often encountered growing under planted ornamental birch trees, as is the case with the specimens in the photos. Its dry caps may reach 10 cm across. They are initially convex with strongly inrolled margins that are quite tomentose and white. The caps are less tomentose elsewhere and with time the hairs rub off. The tomentum of the margins forms a veil-like covering of the gills, which are close, narrow, and initially pinkish before later fading to dull tan in maturity. They gills drop a white spore deposit. Initially pinkish orange to pinkish the caps become more orangish with time and often faintly zonate. Also with time the caps develop a central depression that makes the fruitbodies look funnel-shaped. The stipes are flesh-colored, up to 8 cm tall and 2 cm across. They are smooth and dry. When cut the gills and cap flesh exude a white latex that does not change color. The cap and stipe flesh is white. The fruitbodies do not usually have an odor, but the taste is extremely acrid. The toxicity leads to intense nausea, vomiting, and diarrhea within an hour or so and may last for a full day. Interestingly the fruitbodies are sold in markets in Finland and Russia. In those countries mycophiles use special preparation with parboiling or pickling to reduces the toxicity and permit safe consumption and enjoyment of the peppery taste. The compound responsibe for the toxicity and acrid taste is the sesquiterpene velleral. Sesquiterpenes are a utilized by many fungal species to deter consumption by animals due to their unpalatability and toxicity.