Lactarius deterrimus

Description

Lactarius deterrimus is an edible mushroom that grows under pine and spruce trees. It has a smooth stem and pale carrot-colored gills and produces green-staining orange milk when squeezed. It is found in Europe and some parts of Asia and is used as a food source for larvae of certain insects. It can be identified by its orangish cap that develops green spots and its orange-colored latex that turns maroon. It is different from similar mushrooms in its host tree and latex color. A visually similar species in the United States and Mexico is not closely related to the European species.

This mushroom is usually stir-fried in butter or oil, and young mushrooms can be pickled or dried. The urine may turn red after eating a lot of this mushroom, but it's harmless. Young mushrooms with tightly rolled caps are best for cooking because they are firm and crunchy. Older mushrooms may be more brittle and crumbly.

Lactarius deterrimus caps are considered medicinal mushrooms in folk medicine and Traditional Chinese Medicine (TCM) due to their high vitamin and mineral content. To prevent them from losing their milk and drying out before preparation, they should not be cut when collected.

Common names: Orange Milkcap, False Saffron Milk-Cap, Spruce Saffron Lactarius, German (Fichten-Reizker), Netherlands (Peenrode melkzwam).

Mushroom Identification

1. Cap

   The cap is 2.36 to 3.94 inches (6 to 10 cm) wide and starts off convex before becoming more or less flat or shallowly depressed. It is sticky, bald, and bright orange when young, but fades to a dull orange and develops green stains. It is not zoned, or only faintly zoned near the margin, with an unlined margin.

2. Gills

   The gills of the mushroom are broadly attached to the stem or begin to run down it. They are close, with frequent short gills, and are orange with developing green stains.

3. Stem

   The stem is 1.18 to 1.97 inches (3 to 5 cm) high and up to 0.59 inches (1.5 cm) in thickness. It tapers slightly at the base and is bald, orange overall, with a thin white zone at the apex and developing green stains.

4. Flesh

   The flesh is dirty orange and slowly stains reddish orange.

5. Milk (Latex)

   The milk of the mushroom is carrot orange, becoming reddish after 10 minutes or more, and is scant.

6. Odor and Taste

   The odor is not distinctive. The flavor is slightly bitter to resinous, and sometimes pungent, which is not particularly pleasant.

7. Spore Print

   Pale pinkish buff.

8. Habitat

   The mushroom is mycorrhizal with spruces and grows alone, scattered, or gregariously during the summer and fall. It is widely distributed in Europe in areas where spruces grow.

9. Microscopic Features

   Spores 7–10 x 6.5–7.5 µm; ellipsoid; ornamented with amyloid warts and ridges extending up to about 0.5 µm high; connectors fairly frequent, forming partially reticulate patterns. Cheilomacrocystidia narrowly fusiform; to about 60 x 7.5 µm. Pleuromacrocystidia scattered; inconspicuous; narrowly fusiform; barely projecting. Pileipellis an ixocutis; elements 2.5–5 µm wide.

Look-Alikes

1. Lactarius torminosus

   Has a very shaggy cap and its milk is white.

2. Lactarius deliciosus

   Has a pitted appearance, while green areas on the cap are only present in older specimens.

3. Lactarius semisanguifluus

   Its milk also discolours within 5 to 10 minutes to maroon. The cap of older fruit bodies is nearly completely greenish. It is also common under pines.

4. Lactarius fennoscandicus

   Its cap is distinctly zoned and brown-orange. Sometimes the cap has purple-gray tones. The stem is pale to blunt orange-ochre.

Health Benefits

Antibacterial activity

Scientists used agar disk diffusion assays to test the antimicrobial properties of L. deterrimus against various bacteria and fungi. They found that 500 µg of the mushroom's crude extract inhibited the growth of E. coli, P. vulgaris, and M. smegmatis to a similar degree as 10 µg of penicillin. However, the extract had weaker inhibition against S. aureus, B. cereus, and B. megaterium.

Antioxidant activity

The extract from L. deterrimus has strong antioxidant activity, which was measured using the β-carotene/linoleic acid method. It was as strong as the positive controls BHT and α-tocopherol. Although its radical scavenging activity was relatively low, the reducing power and chelating effect on ferrous ions were strong at certain concentrations.

History

In 1968, Frieder Gröger, a German mycologist, described a species that was previously considered a variety of Lactarius deliciosus (specifically L. deliciosus var. piceus, described by Miroslav Smotlacha in 1946). After the description of L. semisanguifluus by Roger Heim and A. Leclair in 1950, this fungus was referred to as the latter. In 1998, Annemieke T. Verbeken and Jan Vesterholt separated L. fennoscandicus from L. deterrimus and classified it as a separate species.

The epithet of deterrimus is Latin and was chosen by Gröger to highlight the poor gustatory properties of the mushroom, such as the bitter aftertaste and often heavy maggot infestations. The superlative of "dēterior" (meaning less good) means "the worst, the poorest".

Lactarius deterrimus belongs to the Deliciosi section of the Lactarius genus. Molecular phylogenetics studies show that this section forms a specific phylogenetic group within the milk cap relatives. Deliciosi species typically have orange or reddish-colored latex and taste mild to slightly bitter. They form strict mycorrhizal associations with conifers. L. fennoscandicus is the closest relative of L. deterrimus.

Synonyms and Varieties

1. Lactarius deliciosus var. piceus Smotlacha (1916), Atlas hub jedlých a nejedlých, p. 217

2. Lactarius deliciosus ss. J.E. Lange (1940), Flora agaricina Danica, 5, p. 49, pl. 177, fig. A, A1

3. Lactarius semisanguifluus ss. Neuhoff (1956), Die Milchlinge (Lactarii), in Die Pilze Mitteleuropas, Bd. IIb, p. 125, pl. 6.22

4. Lactarius deliciosus var. deterrimus (Gröger) Hesler & A.H. Smith (1979), North American species of Lactarius, p. 94

Photo sources:

Photo 1 - Author: James Lindsey (CC BY-SA 2.5)

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

Photo 3 - Author: AJC1 (CC BY-SA 2.0)

Photo 4 - Author: Björn S. (CC BY-SA 2.0)

Photo 5 - Author: Ericsteinert (CC BY-SA 3.0)