Flammulina populicola

[ Basidiomycetes > Agaricales > Marasmiaceae > Flammulina . . . ]

by Michael Kuo

Like its close cousin, Flammulina velutipes, Flammulina populicola has a fuzzy brownish stem, a white spore print, and a sticky reddish brown cap. In fact there are really only five things that separate the two species:

• Flammulina populicola grows on the wood of Quaking Aspen and other poplars (members of the genus Populus) in western North America, while Flammulina velutipes grows on the wood of hardwoods across North America (excepting the western poplars).
• Flammulina populicola has shorter, wider spores that measure 6-7.5 x 4-5.5 µ (versus 6-9 x 3.5-4 µ for Flammulina velutipes).
• The cells composing the "skin" of the cap in Flammulina populicola are fat and club-shaped; the corresponding cells in Flammulina velutipes are skinny.
• Flammulina populicola will not "mate" with Flammulina velutipes in culture.
• Flammulina populicola and Flammulina velutipes have different DNA signatures.

All of this means that Flammulina populicola is a separate species no matter how you define a "species," since the three most widely recognized "species concepts" for fungi are covered. It is a "biological species" because it can only mate with other Flammulina populicola specimens. It is a "morphological species" because it has observable physical features that separate it (though the features are microscopic). And it is a "phylogenetic species" because its DNA separates it from other Flammulina DNA.

And, as is often the case, the mushroom's ecology appears to separate it, as well. It has evolved with the western poplars, and not in other North American ecosystems. Mushroom identifiers who lack DNA sequencers, fungal culture labs, and microscopes may be able to identify it with confidence on this basis alone.

Flammulina populicola is edible (though not great), and western authors who report on the edibility of Flammulina velutipes are often talking about Flammulina populicola (don't blame them for "mistaking" the mushrooms, since Flammulina velutipes wasn't separated until 1999).

Description:

Ecology: Saprobic on the stumps, logs, roots, and living wood of poplars (members of the genus Populus, like Quaking Aspen and Narrowleaf Cottonwood) from the Rocky Mountains westward; growing alone, scattered, gregariously, or (more commonly) in clusters; often appearing terrestrial when growing from root systems; late summer and fall (common during monsoon season in Colorado). Collections on aspen from the Great Lakes northward should be studied, I believe, as well as collections on Salix from western North America; it would not surprise me if these specimens of "Flammulina velutipes" turned out to be Flammulina populicola and resulted in an extension of the range for the species.

Cap: 1-7 cm; convex, becoming broadly convex to flat; moist and sticky when fresh; smooth; orangish brown to yellowish brown.

Gills: Attached to the stem; whitish to pale yellow; crowded or close.

Stem: 2-11 cm long; 3-5 mm thick; equal or larger towards base; tough; pale to yellowish brown or orange brown when young; becoming covered with a dark, brown to rusty brown or blackish velvety coating as it matures.

Flesh: Whitish to yellowish; thin.

Spore Print: White.

Chemical Reactions: Cap red with KOH.

Microscopic Features: Spores 6-7.5 x 4.5-5 µ; smooth; more or less elliptical. Pileipellis composed of a layer of club-shaped hyphal tips.

REFERENCES: Redhead & Petersen, 1999. (Redhead & Petersen, 1999; Petersen, Hughes & Redhead, 2001.) Herb. Kuo 08160301, 08080502.

Further Online Information:

Flammulina study: Petersen, Hughes & Redhead

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Cite this page as:

Kuo, M. (2006, February). Flammulina populicola. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/flammulina_populicola.html