Kingdom: Fungi
Phylum: Basidiomycota
Class: Basidiomycetes
Order: Agaricales
Family: Marasmiaceae
Genus: Armillaria

Armillaria mellea is commonly called the “Honey Mushroom” or the “Ringed Honey Mushroom.” A. mellea has a smooth and sticky, but sometimes dry cap. It is 1-4 inches wide and the color ranges from yellow to a yellow-rusty-brown. The cap may have stiff black scaly hairs. The gills are off-white and stain yellow to red; attached or slightly descending. The stalk is 2-6 inches long and 1/4-3/4 inches thick. It is white, turning yellowish to yellow-brown with age; has a thick annulus that is white to yellow, changing colors with the stalk as it ages. Stalks often fused at the base, coming to points. The white rhizomorphs are long and flattened. There are no clamps found at the base of the basidia. Spore print is white to cream. Spores are 8-12 × 6-7 micrometers; smooth, elliptic to ovoid, and inamyloid.

A. mellea has many look-alikes of which most are toxic. In many cases basic characteristics of its gross morphology can distinguish, but you must be careful before eating them. Specific examples of similar fruiting bodies and their differences are listed in the “Look-Alikes” section.

Armillaria mellea has been reported throughout the eastern half of the United States and in northern California. It is usually found from August to November. In California it’s found December though February.

A. mellea grows in clusters at the base or stumps of hardwood trees. They have also been seen near conifers. It can be found away from trees, but in close proximity to them.

Armillaria tabescens, the “Ringless Honey Mushroom” is often confused with A. mellea. The difference between the two is the presence or lack of a partial veil which leaves a ring called an annulus.

A. nabsnona See Tom Volk’s “Honey mushroom number nine”

A. gallica See Tom Volk’s page on the humongous fungus

There are also many other Armillaria species.

Omphalotus olearius is orange and lacks a ring. See Tom Volk’s Jack-O-Lantern Mushroom page

Gymnopilus spectabilis is orange and has orange-brown spores. (Halucinogenic). See Tom Volk’s page on the big laughing Gym

Galerina autumnalis is smaller with brown spores. (Poisonous) See Tom Volk’s page on the deadly Galerina

Naematoloma fasciculare (=Hypholoma fasciculare) has greenish-yellow gills and purple-brown spores. (Poisonous)

A. mellea is a delicious edible mushroom, but some people have minor gastrointestinal discomfort if not cooked thoroughly.

A. mellea is a serious parasite of hardwoods.

Bessette, Alan E. et.al. (1997). Mushrooms of Northeastern North America: Armillaria mellea. (pp. 69). Syracuse University Press.

Lincoff, Gary H. (1995). National Audubon Society Field Guide to North American Mushrooms: Armillaria mellea. (pp. 736). Alfred A. Knopf Inc.

http://www.mushroomexpert.com/armillaria_mellea.html

http://mushroomobserver.org/observer/show_observation/4530

Andy Hart
UW-La Crosse Mycology
12/11/08