Lactarius controversus

Description

Lactarius controversus is a widely distributed species of milk mushroom, reported from across North America, Europe, Asia, and North Africa. It is characterized by small spores, white matted-fibrillose to glabrous pileus that is typically stained pinkish to lavender or brownish, and white latex that slowly becomes strongly acrid (Hesler and Smith 1979).

This mushroom is considered inedible in western Europe due to its very acrid taste, but is eaten, and even commercially collected, in south-eastern European countries such as Serbia and Turkey.

Common names: Blushing Milkcap.

Mushroom Identification

1. Ecology

   Mycorrhizal with species of Populus (especially quaking aspen and big-toothed aspen) and Salix; growing alone or gregariously - or sometimes in dense troops; summer and fall; widely distributed in northern and montane North America.

2. Cap

   7-30 cm; at first convex with an inrolled, slightly hairy margin; becoming flat with a central depression, or vase-shaped, with an even and bald margin; slimy to sticky when fresh, but soon dry; rugged with appressed fibers; whitish overall, but often with faint zones of pinkish or purplish, especially near the margin.

3. Gills

   Attached to the stem or beginning to run down it; thin; close or nearly crowded; sometimes forking near the stem; pinkish to pale pink.

4. Stem

   2.5-10 cm long; 1.5-4 cm thick; more or less equal, or tapering to the base; sticky when fresh, but soon dry; usually without potholes, but occasionally with a few; bald; eventually becoming hollow; whitish.

5. Flesh

   White; unchanging on exposure; fairly firm.

6. Milk

   White; unchanging on exposure to air; not staining tissues; not staining the white paper.

7. Odor and Taste

   Odor is not distinctive, or pleasantly fragrant; tastes slowly moderately to strongly acrid.

8. Chemical Reactions

   Cap surface negative to pale yellowish with KOH.

9. Spore Print

   Creamy white or pale pinkish.

10. Microscopic Features

    Spores 6-7.5 x 4.5-5 µ; ellipsoid; ornamentation under 0.5 µ high, as amyloid warts and ridges usually forming partial or nearly complete reticula. Pleuromacrocystidia and cheilomacrocystidia are scattered; not projecting; inconspicuous; aciculate to fusiform, with apical constrictions; to about 45 µ long. Pileipellis an ixocutis.

Look-Alikes

1. Lactarius citrolens

   Inedible, bitter, and spicy taste, initially the smell of rhubarb or lemon, then rotten lemon.

2. Lactarius glaucescens

   Edible but quick, grows only in deciduous forests, smaller and thinner, and fades after yellowish cutting.

3. Lactarius pallidus

   Inedible, bitter and scratchy, grows mainly under beeches, with cuticle and yellower flesh.

4. Lactarius piperatus

   Edible, spicy, but well prepared, smooth cuticle.

5. Lactarius pubescens

   Poisonous, extremely spicy, grows outside forests through grass under birches, the edge of the foot being irregularly wavy like fringed with fringe, biting smell.

6. Lactarius torminosus

   Poisonous, grows under birch, more pink-reddish, fruity smell with shades of turpentine, hot and resinous taste.

7. Lactarius trivialis

   Inedible because too fast, grow only in deciduous trees, with great pleasure under chestnuts, very distant blades, original sponge with cuticle colored gray-pink, but the variation of the chelate is white.

8. Lactarius vellereus

   Inedible, also very fast, bitter, and stingy, blades further apart, woolly-felted cuticle.

Synonyms

1. Agaricus controversus Pers. (1801)

2. Agaricus lateripes Desm. (1823)

3. Galorrheus controversus (Pers.) P.Kumm. (1871)

4. Agaricus lateripes Desm. (1823)

5. Lactarius lateripes (Desm.) Fr. (1874)

6. Lactifluus controversus (Pers.) O.Kuntze (1891)

7. Lactarius controversus var. lateripes (Desm.) Bataille (1908)

Photo sources:

Photo 1 - Author: Strobilomyces (CC BY-SA 3.0, 2.5 Generic, 2.0 Generic and 1.0 Generic)

Photo 2 - Author: Rudolphous (CC BY-SA 4.0)

Photo 3 - Author: Thkgk (CC BY-SA 3.0)