Mushrooms & Other Fungi

Two Amanita Muscaria mushrooms.
Two Amanita Muscaria mushrooms growing alongside a carriage road.

NPS Photo/Lilly Anderson


Fungi’s Role

Acadia National Park is often appreciated for its stunning landscapes, forested coastlines, and unique patchwork of trees. Driving all the biodiversity and life we see above ground, from the towering old growth trees to the wildflower fields, is an underground web of fungal life. The more commonly known function of fungi is that they are decomposers; some break down dead matter into nutrients to be used by new growth. They provide another, lesser known link in the web of life as well. 95 percent of plants form partnerships with fungi through their roots. The fungi act as messengers within a forest through these relationships, allowing trees to send nutrients and warning messages to each other. Forests act as a whole with fungi as the thread connecting all the pieces together.

A cluster of Jack o' Lantern mushrooms on the base of a tree.
A cluster of Jack o' Lantern mushrooms on the base of a tree.

NPS Photo/Lilly Anderson

Mushrooms in Acadia

Acadia is a wonderful place to find and appreciate a variety of these forest floor gems. The best time to look for mushrooms in Acadia is from the early summer through early fall. Wet areas like wetlands, pond edges, and streams can produce exciting finds, especially a few days after rainfall.

Although most mushrooms have a short life span, there are a few species that can be found commonly in Acadia year-round:

  • Red-belted polypores- large, red-rimmed fungi that can be frequently spotted peaking out from the trunks of Acadia’s coniferous trees.
  • Birch polypores- white to gray, smooth and rounded fungi that grow on birch trees.

Some common seasonal finds include:

  • Reishi mushrooms- large, red shelf-like mushrooms with a shiny or dusty exterior.
  • Oyster mushrooms- fungi that grow in clusters and have a distinct fishy smell.
  • Jack o’ Lantern mushrooms- a bioluminescent species that emit a green glow while releasing their seeds in a similar way that fireflies light up.
A Bleeding Tooth Fungus growing among moss.
A Bleeding Tooth Fungus growing among moss.

NPS Photo/Lilly Anderson

Rare Finds

Bleeding tooth fungi are a more rare spooky species with an underside that looks like teeth, and a soft pink top bubbling up with a red liquid that looks like blood. This fungus find can happen in old growth forests, where the bleeding tooths like to trade nutrients to pine trees for sugar. Lobster, a Mount Desert Island staple, can also be found in mushroom form popping out through mossy understories beneath hemlock trees. Lobster mushrooms are a product of fungal cannibalism; the outer red shell is a hypomyces fungus parasitizing some other mushroom.


Above and Below

Mushrooms are simply the fruit of a fungus, and only reveal themselves to us under the perfect conditions. Seeing them often comes down to being in the right place at the right time. Even if you don’t see any of these mushrooms above ground in your exploration of Acadia, there is still a vast web of fungal life underneath your feet—recycling life and sending messages throughout the forest.

A mass of bright yellow slime mold on a leafy forest floor.
Dog-vomit slime mold

NPS Photo by Jack Byrley

Slime Mold

Amorphous, bright yellow, and frequently seen in damp weather, slime mold can be quite baffling to the unfamiliar viewer. In spite of its name, slime mold is not, in fact, a mold. It is not a fungus at all, nor is it a moss, algae, or lichen.

Genetic analysis suggests its closest relatives are amoeba, single celled free-living organisms that are frequently found in pond water. The easiest slime mold to observe is the dog-vomit slime mold, easily distinguished from rotting wood and the forest floor with its brilliant yellow color. However, other species of slime molds may appear as tiny globular clusters that resemble insect eggs, or form shapes similar to coral.

Uniquely, slime molds can function either as microscopic single-celled organisms, or can congregate into a large body visible to the naked eye.


More About Lichen, Mushrooms & Other Fungi

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    Last updated: October 19, 2023

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