Summary: Armillaria gallica, a member of Armillaria mellea group, is difficult to separate macroscopically. Features of this species include relatively small size, a tan to pinkish brown cap that is distinctly hairy, a frequently enlarged stem base which sometimes stains yellow when bruised, a white cobwebby veil at the stem top, and hardwood habitat (usually on soil but sometimes "climbing" onto logs or stumps). It usually does not harm trees to any extent.
Cap: up to 10cm across, ochraceous brown to brownish; fine yellow brown to grayish brown scales, margin not very striate, slightly fleecy, (Courtecuisse), tan to pinkish brown; distinctly hairy, (Berube), reddish brown to pinkish ocher with brown scales at center, (Kibby)
Flesh: firm; whitish, (Buczacki)
Gills: subdecurrent [somewhat decurrent], spotted white to brownish, (Courtecuisse), cream to pinkish buff (Kibby)
Stem: up to 12cm long and up to 2.5cm wide, often bulbous club-shaped; +/- bister, brown in lower part; with bright to grayish yellow fibrils or fleecy scales, (Courtecuisse), base is commonly swollen and sometimes stains yellow where bruised, (Volk), club-shaped to cylindric; rhizomorphs cylindrical with monopodial branching, (Berube), bulbous; pinkish buff, often with a yellow coating at the base, (Kibby)
Veil: ring fibrillose and short-lived (Courtecuisse), cortinate, unpigmented, evanescent [fleeting], (Berube), white, cobwebby veil at stem apex, unlike the thick woolly ring of A. mellea, (Kibby), partial veil is cortinaceous, i.e. similar to the cobwebby cortina of a Cortinarius species, leaving white arachnoid remnants on stem, (Volk)
Odor: faint, mushroomy, fruity, (Buczacki)
Taste: faint, bitter, (Buczacki)
Microscopic spores: spores 7.2-9.5 x 4.8-6 microns, (Volk), clamp connections present on basidia; subhymenial tissue binucleate, pigments in cell wall and in vacuoles, (Berube), spores 7.5-8.5 x 4.5-5 microns, smooth, (Kibby)
Spore deposit: white (Kibby)
Notes: Armillaria gallica has been found at least BC (Morrison), WA (Banik), and OR, CA, and Mexico, (Baumgartner). It is the most widely distributed Armillaria species east of the Rocky Mountains, including the northeast, midwest, and gulf coast, but is very rare in the west, (Volk). It is also found in Europe and North Africa (Courtecuisse).
EDIBILITY
Habitat and Range
SIMILAR SPECIES
Armillaria cepistipes is similar. The key in Volk(2), accessed February 9, 2015, separates it by saying that there is an "often deceptive double-appearing annulus" in NABS XI (he says probably the same as A. cepistipes), whereas in Armillaria gallica the annulus is "arachnoid, not appearing double". Armillaria sinapina has some cells in the annulus greater than 8 microns, whereas Armillaria gallica has no cells in annulus greater than 8 microns, (Volk). See also SIMILAR section of Armillaria ostoyae.
Habitat
single to gregarious, usually on soil, but occasionally "climbing" onto logs or stumps to fruit, almost always found on hardwoods, but occasionally on conifers, (Volk), Garry oak habitat on southern Vancouver Island, (Allen), often occurs singly, parasitic or saprobic; on the ground, but connected to wood by rhizomorphs, (Courtecuisse), rarely grows in clumps but scattered singly over a wide area growing from buried wood or roots, (Kibby), fall (Buczacki)