Honey Mushroom Hunting Guide
What is a Honey Mushroom? How to identify a Honey Mushroom:
Armillaria, is a genus of parasitic fungi that includes the A. mellea species known as honey fungi that live on trees and woody shrubs. It includes about 10 species formerly categorized summarily as A. mellea. Armillarias are long-lived and form some of the largest living organisms in the world. The largest known organism (of the species Armillaria ostoyae) covers more than 3.4 square miles in Oregon’s Malheur National Forest and is more than 2,400 years old. Some species of Armillaria display bioluminescence, resulting in foxfire.
Armillaria can be a destructive forest pathogen. It causes “white rot” root disease of forests, which distinguishes it from Tricholoma, a mycorrhizal (non-parasitic) genus. Because Armillaria is a facultative saprophyte, it also feeds on dead plant material, allowing it to kill its host, unlike parasites that must moderate their growth to avoid host death,
In the Canadian Prairies (particularly Manitoba), Armillaria is referred to often as openky, popinki (Ukrainian: опеньки), meaning “near the stump” in Ukrainian.
The basidiocarp (reproductive structure) of the fungus is a mushroom that grows on wood, typically in small dense clumps or tufts. Their caps (mushroom tops) are typically yellow-brown, somewhat sticky to touch when moist, and, depending on age, may range in shape from conical to convex to depressed in the center. The stipe (stalk) may or may not have a ring. All Armillaria species have a white spore print and none have a volva (cup at base).
Honey fungus is a “white rot” fungus, which is a pathogenic organism that affects trees, shrubs, woody climbers and, rarely, woody herbaceous perennial plants. Honey fungus can grow on living, decaying, and dead plant material.
Honey fungus spreads from living trees, dead and live roots and stumps by means of reddish-brown to black rhizomorphs (root-like structures) at the rate of approximately 3.3 feet (1 m) a year, but infection by root contact is possible. Infection by spores is rare. Rhizomorphs grow close to the soil surface (in the top 7.9 inches (20 cm)) and invade new roots, or the root collar (where the roots meet the stem) of plants. An infected tree will die once the fungus has girdled it, or when significant root damage has occurred. This can happen rapidly, or may take several years. Infected plants will deteriorate, although may exhibit prolific flower or fruit production shortly before death.
The linkage of morphological, genetic, and molecular characters of Armillaria over the past few decades has led to the recognition of intersterile groups designated as “biological species”. Data from such studies, especially those using molecular diagnostic tools, have removed much uncertainty for mycologists and forest pathologists. New questions remain unanswered regarding the phylogeny of North American Armillaria species and their relationships to their European counterparts, particularly within the “Armillaria mellea complex”. Some data suggest that North American and European A. gallica isolates are not monophyletic. Although North American and European isolates of A. gallica may be interfertile, some North American isolates of A. gallica are more closely related to the North American taxon A. calvescens than to European isolates of A. gallica. The increase in genetic divergence has not necessarily barred inter-sterility between isolated populations of A. gallica. Although the relationships among some groups in the genus seem clearer, the investigation of geographically diverse isolates has revealed that the relationship between some North American species is still unclear.
Sign up for newsletters and notifications here:
Honey Mushroom Species (Top 3 in North America):
(Armillaria mellea) Ringed Honeys:
(Armillaria tabescens) Ringless Honeys:
New photos added 12-9-2022: (all taken in Louisiana in October 2020)
Previous (original) galery: