|Major Groups > Gilled Mushrooms > Pale-Spored > Armillaria > Armillaria solidipes|
by Michael Kuo
In most areas of North America, Armillaria solidipes can be separated from other species of Armillaria on the basis of its brown colors, the fairly prominent scales featured on its cap, and the well developed ring on its stem. It is usually found on conifers, and it is a ravaging parasite feared by forest managers across the continent.
In the northeast, from about New Hampshire to North Carolina, the hardwood-loving and apparently benign Armillaria gemina is a "morphologically inseparable" species--which means there is no way to distinguish it from Armillaria solidipes by looking at it (with or without a microscope). However, the two species are unable to "mate" with each other, and are thus clearly distinct--though you may need a mycological laboratory and training in order to figure out which Armillaria you have collected.
Burdsall & Volk (2008) determined through morphological analysis that the 100-year-old type collection of Charles Peck's Armillaria solidipes represents the same species as Armillaria ostoyae, named by Romagnesi in 1970; by the rules of nomenclature the older name takes precedence.
Ecology: Parasitic and saprobic on the wood and roots of conifers (especially spruces) and, less frequently, hardwoods; causing a root rot; typically growing in dense clusters; summer and fall; widely distributed and common in northern and montane North America. The illustrated and described collections are from California, Colorado, and Québec.
Cap: 4-10 cm; convex at first, becoming broadly convex or nearly flat in age; dry or slightly moist; dark brown to cinnamon brown or yellow-brown underneath small, tan to brown or blackish scales; the margin sometimes becoming finely lined.
Gills: Broadly attached to the stem or beginning to run down it; close or nearly distant; short-gills frequent; white or whitish when young and fresh, developing pinkish hues and/or reddish brown spots and discolorations.
Stem: 5-10 cm long; 0.5-1.5 cm thick; more or less equal, or slightly tapered to base; whitish, becoming brownish to gray or nearly black toward the base; finely hairy with brownish fibrils; with a well-developed whitish ring that may feature a yellowish or brownish underside or edge; usually with yellowish mycelium near the base; attached to long black rhizomorphs that run through the wood.
Flesh: Whitish, sometimes becoming pinkish brown with maturity; often yellow in the stem base; unchanging when sliced.
Odor and Taste: Taste mild to slightly bitter; odor not distinctive.
Chemical Reactions: KOH on cap surface negative.
Spore Print: White.
Microscopic Features: Spores 7-10.5 x 4-6.5 µ; ellipsoid; smooth; hyaline in KOH; inamyloid. Basidia often basally clamped; 4-spored. Cheilocystidia ("marginal cells") inconspicuous; 15-25 x 2.5-5 µ; cylindric-flexuous, subclavate, or subfusiform; thin-walled; hyaline in KOH. Pleurocystidia not found. Pileipellis a cutis; golden brownish in KOH; elements 5-10 µ wide, smooth; terminal cells cylindric with rounded apices.
REFERENCES: Peck, 1900. (Moser, 1983; Berube & Dessureault, 1988; Berube & Dessureault, 1989; Breitenbach & Kränzlin, 1991; Volk, 2003; McNeil, 2006; Miller & Miller, 2006; Burdsall & Volk, 2008; Trudell & Ammirati, 2009; Evenson, 2015; Siegel & Schwarz, 2016.) Herb. Kuo 08180703, 08131509, 01161501; Herb. DBG ROMO 2012 5024-34, 5025-34, 5026-14, 5026-25, 5027-24, 5027-31.
Further Online Information:
Armillaria solidipes at Tom Volk's Fungi
This site contains no information about the edibility or toxicity of mushrooms.
Cite this page as:
Kuo, M. (2016, December). Armillaria solidipes. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/armillaria_solidipes.html