Honey Mushroom
Armillaria mellea
A tree's worst nightmare...
... But a yummy treat for us!
QUICK ID:
Color - honey to dark honey
Height - up to 20 cm
Cap diameter - up to 15 cm
Spore print - white
Edibility: Edible
What's in a [common] name?
Armillaria mellea was first described in 1790 by Norwegian-Danish botanist, Martin Vahl, who named it Agaricus melleus. It wasn’t until 1871 that German scientist, Paul Kummer, transferred it to the genus Armillaria. Over the years, a number of subspecies have been reported within this species complex. A. mellea is commonly referred to as the honey mushroom or fungus given the honey color of its cap.
Description and Ecology
Armillaria mellea has a honey colored cap and a white-ish to brownish stalk. It has a ring around its stalk which, when young, is still attached to the cap, hiding its white-ish gills. These mushrooms often grow in clusters at the base of trees, out of the ground, or off of dead logs. Depending on their age, these mushrooms can vary in size. The caps flatten out as they get older and they can sometimes crack. Their flesh is white to slightly pink and does not change color after slicing. Their spore print is always white.
This mushroom can be found abundantly east of the Rocky Mountains, but has been found in every state in the continental United States. It can be found from summer into late fall, and seems to be particularly abundant in September and October in the northeastern United States.
Warning/Look Alikes
Armillaria mellea has a few poisonous look alikes so be extra careful when identifying them. It is best to leave them where they are if you are not sure if your identification is correct. These look alikes include the deadly Galerina (Galerina marginata - distinguishable by its brown spore print), species in the genus Pholiota, and Sulfur tufts (Hypholoma fasciculare). In New England, I have definitely found Pholiota species growing in the same area as honey mushrooms, so please be careful!
The Shaggy Scalycap
Pholiota squarrosa
Photo taken by author.
Science and Medicine
While A. mellea is considered to be a choice edible, the mushroom which we eat is actually the fruiting structure of a deadly plant pathogen responsible for the deaths of many trees each year. It is one of several species in the genus Armillaria that causes Armillaria Root Rot. This rot is considered to be a white rot fungus because it breaks down all parts of the tree including lignin. The mycelia form black string-like structures called rhizomorphs which infect healthy root tissue and feed on the parts of the tree responsible for producing bark and wood. This infection leads to girdling of the trunk at the base of the tree and eventually tree death (UC IPM). Signs of Armillaria root rot include poor tree growth, chlorosis (yellowing) of the foliage, and eventually death (UMN Extension). Unfortunately, there aren’t any effective treatments for trees in urban areas. Prevention strategies include adequate tree watering, mulching around the tree base, and preventing wounds to the roots or trunk (for example from lawnmowers or shovels)(MDC). In addition to being pathogenic, this fungus can also live saprophytically which adds to its difficulty to manage because it can live for decades in soil without a host to infect.
Fun Fact: Organisms in the genus Armillaria can be massive in size. The largest known organism in the world, which belongs to A. ostoyae, is approximately 3.4 square miles large and is estimated to be about 2500 years old.
White spores on Honey Mushrooms
Armillaria mellea
Photo taken by author.
Culinary Uses
These mushrooms should be parboiled before being used in any dish! Boil the mushrooms thoroughly for 20 minutes. I have seen some websites suggest 10 minutes, but I recommend 20 minutes just to be on the safe side. These mushrooms can be mildly distressing when raw, so make sure you cook them!
I’ve cooked these mushrooms and used them in a simple, overnight marinade inspired by the Forager Chef. Combine 1 cup of boiled mushrooms, 1 shallot (julienned), 5 cloves of garlic (minced), 1 tablespoon peppercorns, 1 teaspoon salt, 1 teaspoon red chili flakes, 1 cup olive oil, lemon peel of 1 lemon, juice of 1 lemon, and 1 bunch of dried sweetfern (optional) in a large jar. Mix and set in the fridge overnight. Enjoy the mushrooms as an appetizer or a topping on white fish.
