Lactarius fragilis

[ Basidiomycetes > Russulales > Russulaceae > Lactarius . . . ]

by Michael Kuo

Among the many small, burnt-orange to tawny cinnamon species of Lactarius in North America, this mushroom can require some effort (and probably a microscope) to identify. It has a characteristic smell--but so do several similar species. Lactarius fragilis is fragrant, and smells like maple syrup, especially after it has been picked and dried out. However, other species that look quite similar smell like "curry," or "burnt sugar," or are simply listed as "aromatic" or "spicy." Separating these smells is not always an easy task!

Other features defining Lactarius fragilis include its gills (which are fairly well spaced, and yellowish when young, later becoming colored more or less like the cap), its watery milk, its mild taste, and microscopic details (see below). One author (Bills, 1986) says Lactarius fragilis "can be easily distinguished from L. camphoratus" on the basis of its lighter colors, slightly larger size, more distant gills, and completely reticulate spores--but I have seen many fragilis/camphoratus specimens demonstrating variability in these features. The "fragilis complex" is in dire need of contemporary study, with evidence from DNA comparisons and ecological separators.

On the West Coast, Lactarius rubidus (a larger, redder species with watery milk, associated with Coast Live Oak and Tanoak) is fairly easily recognized; this species passed for many years as "Lactarius fragilis."

Lactarius fragilis is edible, but should not be eaten by beginners, since identification is not easy. The odor alone does not identify it; in fact, the mushroom in my herbarium that emits this odor most flagrantly is this one, in many ways a dead ringer for Lactarius camphoratus or Lactarius fragilis--but not a Lactarius at all, and quite possibly a potentially deadly Galerina.

Description:

Ecology: Mycorrhizal with hardwoods or conifers; growing gregariously or scattered; spring, summer, and fall; probably widely distributed east of the Rocky Mountains, but recorded most frequently from the southeastern United States.

Cap: 2-3.5 cm; at first convex; becoming flat, with a shallow central depression; the margin even or wavy; smooth or slightly wrinkled, especially towards the center; brownish orange, orangeish brown ("burnt umber"); without distinct zones of color, but sometimes darker towards the center.

Gills: Attached to the stem or running slightly down it; close or, more often, nearly distant; yellowish when young, gradually becoming colored like the cap or paler.

Stem: 2-5 cm long; 4-6 mm thick; colored like the cap or paler; more or less equal; smooth; solid when young, becoming hollow.

Flesh: Pale or colored like the cap; thin; fragile.

Milk: Watery or whitish; scant or copious; not staining tissues.

Odor and Taste: Odor "aromatic" (Hesler & Smith, 1979) or "pungent . . . like maple syrup" (Arora, 1986), increasing in potency as the mushroom dries out; taste mild.

Spore Print: Pale yellow or whitish.

Microscopic Features: Spores 6-7.5 µ; more or less round; ornamentation with prominences 0.5-1.0 µ high; connectors forming complete or nearly complete reticula. Pleurocystidia not projecting substantially.

REFERENCES: (Burlingham, 1908) Hesler & Smith, 1979. (Hesler & Smith, 1979; Bills, 1986.) Herb. Kuo 08270208.

Further Online Information:

Lactarius fragilis in Hesler & Smith (1979)

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Cite this page as:

Kuo, M. (2007, September). Lactarius fragilis. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/lactarius_fragilis.html