Lactarius deterrimus

What You Should Know

Lactarius deterrimus is an edible mushroom, but is much less appreciated than the similar L. deliciosus. The first tastes slightly bitter and is often infested by maggots. Like L. deliciosus, this fungus is mainly stir-fried in butter or oil; if it is cooked in water, the flesh becomes very soft. Young fruit bodies can be also pickled, or dried for later use.

As the fungus is often heavily infested by maggots, skilled mushroom pickers prefer young fruit bodies. The urine discolours to red if a large amount of milk caps are eaten, but this is entirely harmless and is not evidence for an impairment to health. The red-coloured azulene compounds, ingested with the mushroom food, are more or less excreted with the urine.

This messy European species is close to Lactarius deliciosus, but differs in several important ways: it grows under spruces (rather than pines), its stem lacks pot-holes, and its cap is usually less zoned and more prone to green staining. Lactarius fennoscandicus is another similar European species, also associated with spruces; its cap is usually more zonate and more brown, and its spores are slightly smaller. Lactarius deterrimus can be found throughout Europe, wherever spruces occur.

Lactarius deterrimus is mainly distributed in Europe, but the fungus has also found in areas of Asia (Turkey, India, Pakistan).

Common names

1. False saffron milk-cap

2. Orange-latex milky

3. Spruce saffron lactarius

4. Gran-Mælkehat (Danish)

5. Peenrode melkzwam (Dutch)

6. Kuuseriisikas (Estonian)

7. Kuusenleppärousku (Finnish)

8. Bitterer Milchling (German)

9. Egļu rudmiese (Latvian)

10. Tallblodriska (Swedish)

11. Çam melkisi/Çintar (Turkish)

Lactarius deterrimus Mushroom Identification

1. Habitat

   The fungus grows with spruce and can often be found along roadsides and young tree plantations.

2. Cap

   6 to 12cm in diameter, convex and then depressed, the cap is yellowish orange zoned with darker areas and nearly always with irregular green patches. Bruised areas also turn greenish.

   Mature specimens often develop sharp-edged irregular wavy margins and usually turn greener in the centre and is blotches elsewhere on the cap surface.

3. Gills

   Shortly decurrent, crowded, bright orange, staining green when bruised, the gills release orange latex that turns wine red within 30 minutes and eventually dark green.

4. Stem

   5 to 10cm long and 8 to 12mm in diameter, the stem surface is smooth and, unlike Lactarius deliciosus, not pitted. There is usually a somewhat paler band near to the top of the stem.

   Lactarius deterrimus, cross-section of stem

   The stems of mature specimens are hollow.

5. Spores

   Subglobose to ellipsoidal, 7.5-10 x 6-7.6µm; ornamented with warts up to 0.5µm tall joined by lines to form an incomplete network.

6. Spore Print

   Pale pinkish buff.

Lactarius deterrimus Taxonomy & Classification

The species was described in 1968 by German mycologist Frieder Gröger. Before this, L. deterrimus was regarded as a variety of L. deliciosus (L. deliciosus var. piceus, described by Miroslav Smotlacha in 1946). After Roger Heim and A. Leclair described L. semisanguifluus in 1950, this fungus was referred to as the latter. L. fennoscandicus was separated from L. deterrimus in 1998 by Annemieke T. Verbeken and Jan Vesterholt and was classified 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".

Several molecular phylogenetic analyses show that L. deterrimus, L. sanguifluus, Lactarius vinosus and L. fennoscandicus form a group of related species, which might include the North American species L. paradoxus and L. miniatosporus. Although L. deliciosus var. deterrimus qualifies as synonym for L. deterrimus, the families that had been characterized in North America as Lactarius deliciosus var. deterrimus are not closely related with the European types. They also seem not to form a monophyletic group.

Lactarius deterrimus belongs to the section Deliciosi of the genus Lactarius. According to molecular phylogenetics studies, this section forms a definite phylogenetic group within the milk cap relatives. Deliciosi species mainly have an orange or reddish-coloured latex and taste mild to slightly bitter. They are strict mycorrhizal associates of conifers. The next closest relative of L. deterrimus is L. fennoscandicus.

Lactarius deterrimus Health Benefits

Antibacterial activity

Using agar disk diffusion assays, the methanolic extract from L. deterrimus has been investigated for antimicrobial activity against Escherichia coli, Micrococcus luteus, Stapylococcus aureus, Salmonella thyphi, Klebsiella pneumoniae, Pseudomonas aeruginosa, Corynebacterium xerosis, Bacillus cereus, Bacillus megaterium, Mycobacterium smegmatis, Candida albicans and Saccharomyces cerevisiae. It was shown that 500 µg of crude extract from the false saffron milk-cap had inhibition comparable to 10 µg of penicillin against E. coli, P. vulgaris and M. smegmatis, as well as weak inhibition against S. aureus, B. cereus and B. megaterium (Dulger et al., 2002).

Antioxidant activity

The antioxidant activity (measured by the β-carotene/linoleic acid method) of the L. deterrimus methanolic extract at 20 mg/ml was as strong as the positive controls BHT and α-tocopherol. Although the radical scavenging activity (measured by the 1,1-diphenyl-2-picrylhydrazyl assay) was relatively low, the reducing power at 4 mg/ml was strong, as was the chelating effect on ferrous ions. This paper also investigated the quantitative yields of total phenolic and flavonoid compounds (Sarikurkcu et al., 2008).

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