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Lactarius

Expert links: Coloured Milk Milk that turns Yellow Purple Staining
  Candy Caps, etc. Small Lactarius More Lactarius

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Lactarius are cool. When you break a piece of the cap off of a fresh mushroom (which is especially easy in Lactarius as I will soon explain) or just scratch the gills with a knife, they bleed! This makes it relatively easy to identify a fresh one. If you have a dainty little mushroom that bleeds red, white or clear, then you might have a Mycena, but generally, if it bleeds between the gills and cap flesh, it's probably a Lactarius.

Lactarius

Not Lactarius (too dainty)

Russula is very closely related to Lactarius and believe it or not, they are not closely related to other gilled mushrooms. They are another order of mushrooms altogether, that just evolved gills to look like other gilled mushrooms.

Russula and Lactarius share a very interesting quality... a great deal of their cells are spheres instead of long stringy fibres, so instead of wanting to fray when you break the stem in half, with lots of stringy bits hanging off the two broken ends, they can make a clean break (often with an audible "snap!") in whatever direction you want to break them. (You can see some clean breaks in the L. indigo photo). They don't favour peeling in stripes of fibres down the stem, or peeling in a string from the edge of the cap towards the centre like most other mushrooms. They just don't care how you break them.  (For the other end of the spectrum see Inocybe). Which means if you throw a Lactarius or Russula really hard against a tree (this is more fun than it sounds, trust me) portions of them might just disintegrate into a million tiny spheres instead of leaving a pile of long stringy things behind. It's one of the reasons I sometimes say "I can't tell you what mushroom you have, but I might be able to tell you what mushroom you used to have".

Like Russula, many Lactarius are famous for being hot like jalapeno peppers, something not shared with many other mushrooms. This is variously referred to as peppery, acrid or hot. It's a really interesting sensation you might have to get used to if you want to identify them, because many Russula and Lactarius look alike but only differ by one being painfully spicy and one not. And the reaction can be delayed up to a minute or so. You start chewing and chewing and after you're sure nothing is happening, BOOM! Hot! (Just make sure to spit it out). Some Lactarius are said to be poisonous, especially the peppery ones (but that may just be for people with stomachs that are sensitive to that spicy flavour). It's interesting to note that many people of Russian descent eat all Lactarius and Russula they find indiscriminately, but they go through a long preparation of boiling, cooking, pickling etc. for a period of months, and it's entirely possible that something in that long process is removing the "pepperiness" and toxins that can upset your stomach if you do not go through that particular preparation.

Most Russula and Lactarius appear to be mycorrhizal, so you will usually find them on the ground under certain trees, often conifers (unless otherwise stated). The caps may be dry or viscid, but there is never a partial veil (on this continent). Not hygrophanous. Adnate to decurrent gills. The cap is often inrolled, and sometimes bearded with hairs. Many stems are scrobiculate (covered with coloured spots). The typical Lactarius has a cap diameter of maybe 5-15cm, if they average smaller or larger, that will be stated. The more of these characters one possesses, the easier it is to identify it on sight as a Lactarius without needing to see the latex. If the mushroom has dried up, it's not going to bleed anymore, so you'll have trouble recognizing it as a Lactarius unless you notice the brittle flesh, and then it can be confused with Russula.

For gastroid (misshapen) and truffle Lactarius, see my page on Gastroid and Truffle Fungi.

Key to Lactarius:

Coloured Milk

First, let's talk about the ones with coloured milk (usually orange or red) the caps often with green staining. Their taste is mostly mild. Yellow milk is just white milk that quickly changed colour. That is the next section.

L. aestivus - summer to early fall, bright orange colours, little inclination to turn green.

L. aurantiosordidus - southern species, smallish, dingy orange cap and milk, staining turquoise-green, with spruce.

L. deliciosus var. olivaceosordidus - found in coastal states

L. deliciosus var. areolatus - found in the Rockies.

Others are reported but not confirmed. Bright to dingy orange, orange to orange-red milk, concentric circles on cap, stem with water spots (scrobiculate), usually turning green as they age.

Lactarius rubrilacteus - red milk, cap dingy orange. The flesh inside the cap can also turn pure green, not just the outside of the mushroom.

L. barrowsii - also a red bleeder, but cap almost white. Prefers pine in the SW US but was found in WA.

Lactarius indigo - blue with blue milk - This does not occur in the PNW, only back east, but you should know about it. Whoever said there is no such thing as blue food didn't know about this mushroom.

 

Milk that turns yellow

Just about every other Lactarius around here has white milk. But sometimes, the milk will change colour to yellow. Don't eat these, they are varying degrees of peppery, and some are said to be poisonous.

This happened in 10 seconds!

Lactarius scrobiculatus var. canadensis - Bearded around the cap edge, and scrobiculate stalk.

Lactarius resimus - a whitish bearded relative. Similar to L. pubescens, but not confined to birch, and somewhat scrobiculate.

Lactarius xanthogalactus ('chrysorheus'/'vinaceorufescens') - orange capped. Possibly related to the candy cap, but a bit bigger with a white stem. Southern.

Purple staining Lactarius - This reaction might not happen in under 10 seconds like the milk that turns yellow, but it's pretty quick... just give it a few minutes. Break the cap, and rub the milk on the gills. The milk itself doesn't turn purple, but it turns any part of itself that the milk touches to purple. It won't turn anything that isn't a part of the mushroom purple, and the milk itself won't turn purple. None of these are very peppery. Most are not large (<10cm).

L. pallescens - mostly white. KOH yellow on cap, with a slimier stem than L. montanus.

L. californiensis - similar CA coastal species may extend up into OR.

Lactarius montanus ('uvidus') - greyish cap, sometimes with lilac or orange tints. Resinous taste? KOH green on cap.

Lactarius cascadensis - big (>10cm), greyish mushroom with cinnamon gills. Under alder.

Lactarius aspideoides/'aspideus'/pallidiomarginatus - cap smooth and yellow.We don't know which of these species is present here, but something is.

Lactarius representaneus - big, bearded cap rim and yellow, scrobiculate stem, probably the coolest of the purple staining ones.

 

Candy Caps and lookalikes - orange, small (~5cm cap width, or if larger, the stem will be slender (<1cm wide). (Small red or brown Lactarius are in the next section). They represent subgenus Russularia and most are mild tasting or only somewhat bitter or acrid unless noted. (Almost everything else is subgenus Piperites).

One of the coolest mushrooms of all time is the Candy Cap. It is an amazing dessert mushroom... that's right, it is eaten as dessert. When dried it smells and tastes like maple syrup! It is often used to make cookies and ice cream and if you ate some you would probably not believe that the only flavouring used in these desserts is a mushroom. The problem is, it only smells like that when cooked or dried, and can be very hard to separate from the half-dozen or so lookalikes that also grow around here. Some people resort to picking every small orange Lactarius they find and drying them day after day, year after year until they get lucky. Some people burn them with a lighter to see if they can induce the smell. But there's hope, there are some slight differences.

Lactarius rubidus ('camphoratus'/'fragilis') - Candy cap. Dry, dull cap. The white milk is very watery like skim milk, not thick like whole milk. When fruiting in numbers, the forest may smell of maple, perhaps because the mycelium itself puts out a slight maple scent. The fresh taste is completely mild.

Lactarius subviscidus - Perhaps the deepest orange colours. Subviscid. Tastes slightly hot after a minute of chewing.

Lactarius substriatus (subflammeus?) - Caps viscid and somewhat striate? The milk eventually stains itself and tissues slightly yellow. Taste slowly, slightly peppery. More than 1 species may be here in this group in S OR and CA.

L. tabidus (theiogalus) - dry cap, milk slowly stains yellow.

L. luculentus var 'laetus' - perhaps the brightest or palest orange caps. Viscid. Tastes slightly bitter after a minute of chewing. Local mushrooms may need a new variety name.

L. luculentus var luculentus - similar, may taste slightly hot or bitter, off-white spore print.

Lactarius alpinus var mitis - dry cap, under alder, usually mild. Cap sometimes scaly and papillate. Other varieties and/or an unnamed similar species may also occur here.

 

Other small Lactarius - ~5cm cap width, or if larger, the stem will usually be slender (<1cm wide).

First are small, reddish brown Lactarius, not quite as orange as the candy cap and its lookalikes. They are almost always dry capped. They are related to the candy cap group.

Lactarius rufus - the largest of the group and the most red. Be careful, this mushroom has the hottest taste of all! Habanero pepper spicy. It is larger than the others, but it's still more slender than most Lactarius and the colours are close to a candy cap but more brick red.

Lactarius occidentalis - mild, only near alder trees which makes it a little harder to find, and the dullest brown colour.

L. carbonicola - rare, similar east coast species to be looked for. Sometimes on burnt ground.

Lactarius atrobadius - dark brownish-orange, viscid and mild.

L. hepaticus - if it occurs here, is dry capped and slightly acrid.

These small Lactarius are not related to the candy cap group.

Lactarius glyciosmus - grey, with an occasional hint of lilac, prefers birch. Smells just like coconut! Slightly peppery.

Lactarius lepidotus - small, brown, powdery to scaly on the cap! Described from Mt. Rainier under alder.

Lactarius fallax group ('lignyotus') - a gorgeous, mostly mild mushroom with a dry, suede felty cap when young. There are 2 cryptic varieties here, not separated by the occasional gill margination. In a distinct subgenus, Plinthogalus.

Lactarius pseudomucidus - slimy all over, somewhat peppery. Distinctive because of the beautiful contrast between dark cap, pure white gills, and dark stem.

 

More Lactarius - up to 10cm or more, but if not, the stems will usually be stocky (>1cm thick).

Lactarius rufus - often >5cm, brick red and the hottest taste of all!

L. hysginus - 2 varieties of this red-brown species are rumoured to be here.

Lactarius pallidiolivaceus - olive-grey with a very tough stem and scanty milk that stains tissues dark. Usually mild, cap minutely velvety (related to L. fallax).

L. payettensis - viscid, pale olive-buff cap with coarse hairs around the margin that darken in age, very acrid, milk stains gills dark, white stem with ochre spots stains dark yellow-brown.

Lactarius necator (turpis/plumbeus)/olivaceo-umbrinus - beautifully ugly dark greenish orange under birch/conifers. L. olivaceo-umbrinus's milk slowly changes greenish. Peppery.

L. sordidus - yellow-green cap

Lactarius pubescens - bearded species, milk may slowly yellow. Very pale with a hint of pinkish orange, only found under birch, peppery and inedible. Our two varieties may or may not be distinct.

Lactarius torminosus - related, may be darker orange, also bearded, somewhat concentrically zoned, usually under different hardwoods, peppery. Our two varieties may or may not be distinct.

L. subvillosus - similar orange zoned, somewhat bearded cap, but with a scrobiculate stem. Very peppery. Southern.

Lactarius olympianus - zoned orange cap that is not bearded and the stalk is white. Peppery. See also L. trivialis below, which is milder.

Lactarius alnicola - yellowish, the milk might stain yellow slowly. Usually zoned. Like L. olympianus when orangish. Like L. scrobiculatus when slightly bearded or scrobiculate (which it is related to). Peppery.

Lactarius controversus - BIG, and very pale, usually with nice pink gills. Looks like Russula brevipes except for the pink gills (or Hygrophorus saxatilis). Under hardwoods. Peppery.

Lactarius pseudodeceptivus - without the pink gills, under conifers, said to taste quickly acrid.

L. argillaceifolius var megacarpus - quite large, also purplish-grey, not usually zoned. Gills really stain brown. Southern oak species.

Lactarius vietus - grey, birch species with milk that turns grey and stains the gills grey

Lactarius kauffmanii -  related to L. pseudomucidus but larger with pale stem. Viscid all over. Peppery. White spores.

L. kauffmanii var sitchensis - under spruce with creamy-yellow spores, may or may not be distinct.

L. mucidus - smaller, pale cap margin?, milk staining yellow or green. Two possible varieties.

L. caespitosus - buff spore print.

L. glutigriseus - middle of stem coloured, top and bottom pale.

Lactarius affinis - cinnamon orange cap, cinnamon tinged stem. No zoning.

L. trivialis - similar but maybe darker in youth.

L. flexuosus - greyish brown cap with lilac tones, zoned especially near the margin, tinge of colour in the gills, with birch and cottonwood.

L. circellatus var borealis - similar, deeper lilac colours?

Congratulations! You made it through all of the common (and most distinctive rare) species of Lactarius in the PNW. For specialized literature for those of you who just can't get enough milky caps, get a copy of Bessette et. al. "Milk Mushrooms of North America".

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