Poisonous mushroom. If you suspect poisoning, call 112 and take the leftover mushrooms to the doctor.
Description
The woolly milkcap has a cap 4–10 cm across, flesh-pink to orange-reddish, with darker rings and a strongly inrolled, woolly-haired margin. The gills are whitish to pale cream, and the stem is pale pink or white. When damaged it exudes a white milk that does not change colour and burns very strongly in the mouth.
It grows from July to November under birches, on acidic soils, usually among mosses, also in parks. In Poland it is common.
It is similar to the saffron milkcaps, but the woolly hairs on the margin and the burning milk distinguish it from them. Raw it causes nausea, vomiting and diarrhoea. It is regarded as poisonous and we do not recommend eating it.
Identification features
- Cap
- Diameter 4–10 (up to 15) cm; convex with a depressed centre, funnel-shaped with age. Skin felty, slightly sticky in wet weather, with darker concentric zones that fade with age. Margin strongly inrolled, in young specimens covered with hanging woolly fibres. Colour flesh-pink, pink-orange to brown-red, fading to orange-ochre in older ones, paler towards the margin.
- Hymenophore (underside of the cap)
- Gills crowded, with short gills between, thin, slightly decurrent onto the stem, sometimes forked at the stem; whitish or pale cream, then with a pink tint, buff with age; edges smooth.
- Stem
- Height 4–8 cm (1.5–8 cm according to some descriptions), thickness about 1.2 cm (0.6–2 cm according to some descriptions), cylindrical, brittle; surface dry, smooth to finely frosted. Colour pale pink, ochre-pink or whitish, sometimes spotted. In young fruiting bodies solid, then hollow. No ring.
- Flesh
- White to flesh-coloured, firm, brittle, with an irregular break (made up of spherical cells). Smell fruity or turpentine-like, taste acrid, burning. With FeSO4 it turns grey-yellowish. Do not taste it. Milk white to cream, at first abundant, does not change colour in the air and does not stain the gills, burns strongly on the tongue and in the throat.
- Spore print and spores
- Spore print cream to pale yellow. Spores broadly ellipsoid, with low warts joined by an incomplete net (only the ornamentation is amyloid). Dimensions about 7–10 × 6–7 µm (descriptions give different ranges).
Habitat and distribution
Ecology. Mycorrhizal fungus; most often with birch, according to some descriptions also with hemlock (Tsuga), and in North America sometimes with quaking aspen. Grows on acidic, sandy or clay soils, usually among mosses, also in parks by birches. Sometimes parasitised by Hypomyces lateritius or Hypomyces lithuanicus. The fruiting bodies are eaten by squirrels and are also a breeding place for fly larvae.
Distribution. The whole northern hemisphere in the temperate and boreal climate; also reported from Australia. Common in Poland. Not legally protected in Poland.
Fruiting. In Poland from July to November.
What can it be confused with?
- Lactarius deliciosus (saffron milkcap) and Lactarius deterrimus (false saffron milkcap) — Species confused with the woolly milkcap. The woolly hairs on the cap margin and the burning taste easily distinguish it from them; detailed features of the milk of the saffron milkcaps: no data.
- Lactifluus bertillonii (burning milkcap) — Has similar woolly hairs and a burning taste, but is much paler.
- Lactarius acerrimus (acrid milkcap) — Has gills joined in a fork-like way and discolours brown when damaged.
- Lactarius pubescens — Very similar, but paler, with smaller spores (6.0–7.5 × 5.0–6.5 µm).
- Lactarius scrobiculatus — Young fruiting bodies similar, but the white milk quickly turns yellow in the air, and the stem has shiny, sunken spots.
- Lactarius controversus, L. mairei, L. torminosulus — L. controversus has a less hairy margin and cream-white gills; L. mairei is rarer, grows under oaks on calcareous soils; L. torminosulus is a dwarf Arctic variety associated with dwarf birch.
Never rely on a single feature. If you are not sure — do not pick it; show the mushroom to a qualified mushroom expert.
Interesting facts
- Since 2011, after the taxonomic revision of the brittlegill family, it has been the type species of the genus Lactarius.
- The epithet torminosus means "causing colic"; Gray's old English name of 1821 was "bellyach milk-stool".
- In Finland it is collected for sale after special preparation (boiling, soaking in brine).
- The dominant volatile compound of the smell is 1-octen-3-one (about 90%), typical of many mushrooms.
Gribo does not assess edibility. Identification from a photo — also in the app — does not replace a mushroom expert.
Look-alikes: Woolly Milkcap and similar species
Frequently asked questions
When does Woolly Milkcap grow?
According to observations in Poland (GBIF) the season is: July – October; most records fall in September.
Where does Woolly Milkcap grow?
Mycorrhizal fungus; most often with birch, according to some descriptions also with hemlock (*Tsuga*), and in North America sometimes with quaking aspen. Grows on acidic, sandy or clay soils, usually among mosses, also in parks by birches. Sometimes parasitised by *Hypomyces lateritius* or *Hypomyces lithuanicus*. The fruiting bodies are eaten by squirrels and are also a breeding place for fly larvae.
What can Woolly Milkcap be confused with?
The most often mentioned look-alikes are: Saffron milk cap (Lactarius deliciosus), False Saffron Milkcap (Lactarius deterrimus). Never rely on a single feature — if in doubt, show the mushroom to an expert.
Is Woolly Milkcap poisonous?
Yes — a poisonous mushroom. If you suspect poisoning, call 112 and take the leftover mushrooms to the doctor.
In the Gribo app this species also has a 3D model you can rotate, photos in the quiz and warnings when identifying with the camera. See how to get started.