Armillaria Gallica: The Ultimate Mushroom Guide

About The Armillaria Gallica Mushroom

There are many forms of Honey Fungus, and in the past, they all shared the scientific name Armillaria mellea. Nowadays it is generally accepted that there are several distinct species, one of which, Armillaria gallica, is distinguished by having a bulbous or swollen stem base.

Armillaria gallica is usually a late-fruiting species, appearing in the colder weather of late fall and early winter—or even in the depths of winter, during warm spells. In urban areas it is not uncommon in places where hardwood trees were removed several years beforehand, popping up as a "lawn mushroom" without any immediately obvious relationship to rotting wood—through the tree's decaying root system is the actual substrate for the fungus.

Usually found solitary on the ground. A. gallica has a remarkable history. A specimen discovered in Crystal Falls, Michigan was found to be more than 1,500 years old and the size, 9,700 Kilograms (a mass greater than a blue whale) made it the "largest organism in the world." These statistics were published by Smith, M.L., J.N. Bruhn & J.B. Anderson (1992). (L. Biechele, pers. comm.)

Other names: Honey Mushroom.

Armillaria Gallica Identification

1. Ecology

   "Usually an innocuous saprophyte, living on organic matter in the soil and not harming trees to any great extent" (Volk & Burdsall, 1993); growing on the wood of hardwoods and occasionally on conifer wood; appearing alone, gregariously, or in loose clusters; often appearing terrestrial (but actually attached to roots)—but sometimes fruiting from the bases of trees and stumps; late summer, fall, and winter; widely distributed east of the Rocky Mountains.

2. Cap

   3–10 cm; convex, becoming broadly convex or nearly flat; dry or sticky; bald underneath scattered, tiny, yellowish to brownish scales and fibrils (often concentrated over the center); pinkish-brown to tan or, occasionally, yellowish; fading markedly as it dries out; the margin sometimes featuring whitish to yellowish partial veil material when young, becoming lined with age.

3. Gills

   Running down the stem or nearly so; close; short-gills frequent; whitish, discoloring pinkish to brownish.

4. Stem

   4–7 cm long; 1–3 cm thick; usually club-shaped, with a swollen base; finely lined near the apex; with a yellow ring zone or, occasionally, with a flimsy white ring that features a yellow edge; whitish to brownish when fresh, becoming dark watery brownish to olive-gray from the base upward; base sometimes staining yellow; often attached to black rhizomorphs.

5. Flesh

   Whitish; unchanging when sliced.

6. Odor and Taste

   Odor not distinctive; taste not distinctive, or slightly bitter.

7. Chemical Reactions

   KOH on cap surface yellowish to golden, or negative.

8. Spore Print

   White.

9. Microscopic Features

   Spores 7–10 x 4–6 µm; ellipsoid with a fairly prominent apiculus; smooth; hyaline to yellowish in KOH; inamyloid. Basidia 4-sterigmate; basally clamped. Cheilocystidia 15–40 x 2.5–5 µm; cylindric-flexuous to somewhat irregular or contorted; smooth; thin-walled; hyaline in KOH. Pleurocystidia not found. Pileipellis a cutis or ixocutis with areas of upright elements; cutis elements 5–15 µm wide, smooth, hyaline to brownish, with terminal cells cylindric with subclavate to slightly narrowed apices; upright elements 5–15 µm wide, smooth or finely roughened, brownish in KOH, often slightly constricted at septa, with terminal cells cylindric with rounded or slightly narrowed apices.

Armillaria Gallica Toxicity

Although all Armillaria species were for many years generally considered edible when thoroughly cooked, members of the honey fungus group (including Armillaria mellea, the type species of this genus) that occur on hardwoods are considered by some to be suspect, as cases of poisoning have been linked to eating these fungi; this is most probably due to a small but significant proportion of people being adversely affected rather than a universal human reaction to these fungi. We, therefore, recommend that Armillaria gallica is not collected for the pot.

Armillaria Gallica Taxonomy & Etymology

This species, formerly recorded in many field guides as a form of Armillaria mellea, was described in 1987 by Helga Marxmüller and Henri Romagnesi (1912 - 1999), who gave it the currently-accepted binomial scientific name Armillaria gallica.

Synonyms of Armillaria gallica include Armillaria bulbosa (Barla) Kile & Watling, Armillaria inflata Velen., Armillariella bulbosa (Barla) Romagn., and Armillaria lutea Gillet.

The specific epithet gallica comes from the Latin noun Gallia which means that it is French; France is indeed the geographical location (known as the type locality) where the type specimen of Armillaria gallica came from.