Lactarius piperatus

What You Should Know

Lactarius piperatus or Peppery milkcap is an edible mushroom that is quite popular in India and certain eastern European countries. This eastern North American fungus is found in oak-dominated forests and looks, on casual inspection, like several other white species in the genus. As its name suggests, the taste of this species is peppery-excruciatingly so; you are not likely to test it more than once.

There are other large white milk caps but none have their gills as crowded together as the peppery milkcap.

Common names: Peppery milkcap, Peppery milky, Pfeffermilchling (German).

Lactarius piperatus Mushroom Identification

1. Cap

   10 to 16cm in diameter, convex with a tightly inrolled margin and later depressed or funnel-shaped, the creamy-white caps have a fine matt surface. Older specimens often develop reddish patches.

   Beneath the cap cuticle the white flesh is thick and brittle.

2. Gills

   The very narrow, decurrent, crowded gills are a distinguishing feature of this milkcap mushroom; they are white at first, becoming brown with age.

   When damaged, the gills exude very hot and acrid white milk that turns pale green after an hour or two.

3. Stem

   2 to 3cm in diameter and 4 to 8cm tall, the fairly smooth stems taper in slightly towards the base; they become hollow as the fruiting body ages.

4. Spores

   Ellipsoidal, 8-9 x 6-7µm; ornamented with a few small warts and narrow ridges to 0.5µm tall that have some cross connections forming a very incomplete network.

5. Spore print

   White.

Lactarius piperatus Life Cycle

This species is mycorrhizal: It exists most of the time as a network of cells (mycelium) connected to tree roots, in a symbiotic relationship with the tree. (Many trees fare poorly without their fungal partners.)

When ready to reproduce, the mycelium sends up the mushroom — this is the reproductive structure.

Spores are produced in these structures and are released to begin new mycelia elsewhere. The mycelium of a mushroom can live for decades.

Lactarius piperatus Similar Species

The other larger white milkcaps then the two that would lead to possible confusion are the Blushing Milkcap (Lactarius controversus) and the Fleecy Milkcap (Lactarius vellereus).

The Fleecy Milkcap is generally a much larger mushroom with a 'fleecy' feel to the cap, especially towards the margin, the stem is 'shorter' in proportion to the rest of the mushroom. The gills of the Peppery Milkcap are much more crowded than than both of the possible look-alikes.

The Blushing Milkcap often appears like it has been 'bruised' with pink/purple colour on the cap and stem, the stem is shorter and the gills are not as closely packed, it is also mainly found with Poplar, Aspen and Willow.

Sources:

Photo 1 - Author: Jimmie Veitch (jimmiev) (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 NIS from Serbia (Creative Commons Attribution 2.0 Generic)