Lactarius piperatus

What You Should Know

Lactifluus piperatus is a type of fungus that belongs to the Lactifluus genus. Although it is edible, many people do not like its taste, but it can be used as seasoning when dried. The mushroom is creamy-white and funnel-shaped when it matures, with very crowded gills. When cut, it releases a white, peppery-tasting milk. It is found in many parts of Europe and eastern North America, and has been accidentally introduced to Australia. This fungus has a symbiotic relationship with certain deciduous trees, such as beech and hazel, and is found on the forest floor in deciduous woodland.

During the 19th century, people used L. piperatus as a remedy for tuberculosis, but it was found to be ineffective. However, in modern times, it has been discovered that L. piperatus can act as an antiviral agent, and its latex has been used to treat viral warts.

Other names: Peppery Milkcap, Peppery Milky, Blancaccio, German (Pfeffermilchling), Netherlands (Gepeperde melkzwam).

Lactarius piperatus Mushroom Identification

1. Cap

   The cap of this mushroom ranges from 1.57 to 5.91 inches (4 to 15 cm) in size and starts broadly convex before becoming flat, shallowly depressed, or vase-shaped. It is dry, with an even margin, and is typically bald and white or whitish, though it may discolor slightly yellowish or brownish with age.

2. Gills

   The gills of this mushroom are attached to the stem or run slightly down it, and are very crowded, forking frequently. They start white but become pale cream as the mushroom ages.

3. Stem

   The stem is 0.79 to 3.15 inches (2 to 8 cm) in length and 0.39 to 0.98 inches (1 to 2.5 cm) in thickness and is white. It is more or less equal in width, or tapers slightly towards the base, and is bald without any potholes.

4. Flesh

   The flesh of this mushroom is thick, hard, and white, though it may discolor yellowish with age.

5. Milk (Latex)

   When the mushroom is cut or broken, it exudes a copious amount of white milk that does not stain tissues, though it may slowly change to a yellowish color over time.

6. Odor and Taste

   The mushroom has no distinctive odor but has an excruciatingly acrid taste.

7. Spore Print

   White.

8. Habitat

   This mushroom forms a mycorrhizal relationship with oak trees and other hardwoods and can be found growing scattered, gregariously, or in dense groups during the summer. It appears to have a wide distribution in North America, Europe, and Asia.

9. Chemical Reactions

   KOH pale magenta on cap surface.

10. Microscopic Features

    Spores 5-10 x 5-8 µ; broadly ellipsoid; ornamentation less than 0.5 µ high, as scattered warts and lines that occasionally form vague patterns but do not form reticula. Pleuromacrocystidia up to about 70 µ long; subcylindric. Cheilocystidia similar. Pileipellis a hyphoepithelium with the upper, cutis-like layer very thin and the lower, cellular layer easily demonstrated.

Lactarius piperatus Look-Alikes

1. Lactarius vellereus

   Has a thick stem, a woolly cap, and less crowded gills than Lactarius piperatus, but it is not as tall.

2. Russula delica

   Has a similar color and shape to L.piperatus, but its gills are adnate and bluish-green, and it does not produce milk.

3. Lactarius deceptivus

   Similar in appearance, but it has less crowded gills, and a firmer cap margin and its milk is less acrid than Lactarius piperatus.

4. Lactarius glaucescens

   It is nearly identical but features milk that dries green.

Lactarius piperatus Taxonomy

This species was named Agaricus piperatus by Linnaeus in 1753, which means "peppery". For a long time, it was thought that another naturalist named Scopoli had described it first, but new rules changed the starting date for naming fungi, making Linnaeus the official namer. This species was originally considered the type species of the genus Lactarius, but now it is the type species of Lactifluus, a genus that contains mostly tropical mushrooms but also some from the north temperate zone. Recent research has shown that there are actually many different lineages of this mushroom around the world, suggesting that some populations in North America may be different species.

Lactarius piperatus Synonyms and Varietes

• Agaricus piperatus Linnaeus (1753), Species plantarum exhibentes plantas rite cognitas ad genera relatas, 2, p. 1173 (Basionyme) Sanctionnement : Fries (1821)

• Agaricus amarus Schaeffer (1774), Fungorum qui in Bavaria et Palatinatu circa Ratisbonam, 4, p. 36, tab. 83

• Amanita piperata (Linnaeus) Lamarck (1783), Encyclopédie méthodique, Botanique, 1, p. 104

• Agaricus acris Bulliard (1784), Herbier de la France, 5, tab. 200

• Agaricus infundibuliformis Hoffmann (1789), Nomenclator fungorum, 1, p. 110

• Lactarius piperatus (Linnaeus) Persoon (1797), Tentamen dispositionis methodicae fungorum, p. 64

• Hypophyllum piperatum Paulet (1808) [1793], Traité des champignons, 2, p. 165, tab. 68, fig. 2-3

• Galorrheus piperatus (Withering) Fries (1827) [1825-26], Stirpes agri femsionensis, 3, p. 57

• Agaricus pergamenus Hornemann (1839), Flora danica, 38, p. 10, tab. 2268, fig. 2

• Lactarius piperatus var. amarus (Schaeffer) Gillet (1874), Les hyménomycètes, ou description de tous les champignons (fungi) qui croissent en France, p. 216

• Lactarius pergamenus ss. Romagnesi (1980), Bulletin trimestriel de la Société mycologique de France, 96(1), p. 94

Sources:

Photo 1 - Author: Jimmie Veitch (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 2 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)

Photo 3 - Author: Vicpeters (Creative Commons Attribution-Share Alike 3.0 Unported)

Photo 4 - Author: Gljivarsko Drustvo (Creative Commons Attribution 2.0 Generic)