Mushroom Monday: Ugly Milkcap

Mushroom Monday: Ugly Milkcap

Today’s Mushroom Monday mushroom is the Ugly Milkcap (Lactarius turpis).  Although the mushroom might not be pretty, it’s one of many mushrooms that serves an important role in the health of trees.

What Do Ugly Milkcap Mushrooms Look Like?

Ugly milkcap mushrooms, look, well, ugly.  More specifically, they are greenish brown in color with cap edges that are slightly lighter.  Their caps are around two and three quarters to seven inches across, are hairy, and can develop a depression in the middle with a bump (called an umbo) as it ages.  The mushroom’s cap has a slimy feel when it gets wet, and it can glisten in the sunshine.  The cap can turn black as the mushroom ages.

The gills of the mushroom are narrow and packed together.  They have a cream-like color and can turn sepia if bruised.  When the gills are young they have a whitish color, but as they age they turn brown.  When the gills are damaged, they release a latex liquid that starts out white and becomes olive colored when it dries.

The stem is around one and a half to two and three quarters inches tall, has a cylinder shape that tapers at the base, is hollow, and generally has the same color as the stem, but can be lighter.  The stem can be smooth but can also have pits called scrobiculae.  The stem doesn’t have a ring.

What Kind of Relationship do Ugly Milkcap Mushrooms Have With Trees?

Ugly milkcap mushrooms have a mycorrhizal relationship with trees.  They are mainly associated with birch, but can also have a relationship with spruce and pine.

With this relationship, the mushroom gets carbon and sugars from the tree, and the tree is able to take in more nutrients and water because of the mushroom.

Mushrooms with mycorrhizal relationships with trees can be categorized in different ways.  One way has to do with how the mushroom connects to the roots of the tree.

In some cases, the mushroom connects to the tree on the outside of the tree’s roots.  These mushrooms are ectomycorrhizal mushrooms.  In other cases, the mushrooms connect inside the roots.  These mushrooms are endomycorrhizal mushrooms.  Ugly milkcap is an endomycorrhizal mushroom.

In addition to helping a tree take in more nutrients and water, mycorrhizal mushrooms have other benefits for trees.  These include things like helping a tree to resist pathogens, to tolerate drought better, to tolerate stress from salt better, and helping to improve the structure of the soil around a tree.

Although ugly milkcap mushrooms aren’t pretty, they, like other mycorrhizal mushrooms, can play an important role in the health of a tree.  If you have mushrooms around your trees, an arborist can help identify what they are and what their relationship to a tree might be.

Where can Ugly Milkcap Mushrooms be Found?

Ugly milkcap mushrooms can be found at the edges of woodlands in wet areas with soil that is acidic.  In particular, they can be found around birch trees.  They can be found in Europe.

If you liked learning about the ugly milkcap mushroom, check out our post about the saffron milkcap, as well as our other Mushroom Monday posts.  Also, follow us on Facebook to keep with our TrueTreeTalk blog posts and other information from ArborTrue.