Lactarius lignyotus

What You Should Know

Lactarius lignyotus is a member of the large milk-cap genus Lactarius in the order Russulales. It was first described scientifically by Elias Magnus Fries in 1855. It is considered edible, but of little interest. It is a dark brown, velvety Lactarius that grows under conifers and features fairly well-spaced gills, a long stem that is nearly as dark as the cap. It exudes white milk that usually stains the flesh and the gills pinkish.

In North America, we have a big mess on our hands when it comes to lignyotus-like mushrooms, and the species complex is begging for a thorough contemporary investigation based on analysis of carefully documented collections from many locations.

The "typical" variety of Lactarius lignyotus is described below--adapted somewhat to reflect what I believe is substantial variability in several physical features-- followed by an accounting of some of the morphology-defined varieties and related species in North America. The western version of Lactarius lignyotus is Lactarius fallax; it has close or crowded gills.

Other names: Velvet Milkcap, Chocolate Milky.

Lactarius lignyotus Mushroom Identification

1. Ecology

   Mycorrhizal with conifers, especially spruces and firs; terrestrial but not infrequently found growing from well-rotted wood near the ground; late summer and fall; widely distributed in northeastern North America, west to about Wisconsin.

2. Cap

   2-10 cm; convex with a small point in the middle, becoming flat or shallowly depressed, with the central point remaining or disappearing; dry; finely velvety; often with a rugged or wrinkled surface; nearly black when young, dark brown to brown in age; the margin sometimes becoming ridged.

3. Gills

   Attached to the stem or beginning to run down it; close or nearly distant; white or whitish, remaining pale until old age, when pinkish to orangish hues often result from drying milk and spore maturation; occasionally with brownish edges; usually staining slowly reddish to pinkish when damaged but sometimes not staining.

4. Stem

   4-12 cm long; up to 1.5 cm thick; more or less equal; dry; textured and colored like the cap, except for a whitish base; often with small ribs at the apex.

5. Flesh

   White; usually changing slowly to pinkish on exposure (especially in the base of the stem) - but the change is sometimes absent, slight, or very, very slow to develop.

6. Milk

   White; often drying pinkish; staining white paper brown over time.

7. Spore Print

   The spore print is variable, described as white to orangish-yellow to pinkish buff.

8. Microscopic Features

   Spores 8-10 µ; globose or broadly elliptical; ornamentation 1-2 µ high, as amyloid spines and ridges forming partial reticula. Pleuro- and cheilocystidia scattered to abundant but not projecting; irregular (usually contorted versions of "cylindric"). Pileipellis an epithelium with cylindric to clavate terminal elements inflated up to 40 µ wide; brown in KOH. Lactiferous hyphae prominent; ochraceous in KOH.

9. Similar Species

   Lactarius fuliginosus has a light brown stem, and the hat color is dark brown.

Sources:

Photo 1 - Author: Gerhard Koller (Gerhard) (Creative Commons Attribution-Share Alike 3.0 Unported)

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

Photo 3 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International)

Photo 4 - Author: Jerzy Opioła (Creative Commons Attribution-Share Alike 4.0 International, 3.0 Unported, 2.5 Generic, 2.0 Generic and 1.0 Generic)

Photo 5 - Author: James Lindsey (Creative Commons Attribution-Share Alike 2.5 Generic)