Recently we were surprised to find blue mushrooms beneath white pines on our daily walk near our lake home in North-Central Minnesota. Research on-line allowed identification of it with reasonable confidence as the indigo milk cap (Lactarius indigo).
We first noticed this indigo milk cap September 5, 2024. You can see that it is right next to pinecones dropped from nearby Eastern White Pine trees.
The next day we took a closer look at it, the picture above shows light-blue gills on the under-side of the indigo milk cap.
Using a knife to split the mushroom in halves revealed more intense blue coloring.
According to Wikipedia, the indigo milk cap typically has a mutually beneficial relationship with nearby trees. It breaks down minerals from the soil to make them more readily available to trees. In this case, I believe that white pines are the beneficiary.
The mushroom is reportedly edible, and there are even on-line sites that provide recipes for them. Personally, blue mushrooms are a little too strange for me to trust.
North MN Outdoors 