Major Groups > Boletes > Suillus > Suillus subaureus


Suillus subaureus

[ Basidiomycetes > Boletales > Suillaceae > Suillus . . . ]

by Michael Kuo

Here is one species of Suillus that does not always associate with conifers; it is often found under quaking aspen or big-toothed aspen, without any conifers in the vicinity. Salient physical features for Suillus subaureus include the orange pore surface; the yellow cap that develops red streaks and spots; and the ringless stem that develops glandular dots with maturity.

Snell & Dick (1970) theorized that fruitings of Suillus subaureus without conifers present were probably limited to areas "where white pines once grew." However, Baroni & Both (1998), noting that the mushroom's range corresponds to the range of eastern white pine and that Peck described the species in the late 18th century as associated with white pine, theorize that "[w]ith the disappearance of large tracks [sic] of white pine during the 19th and early 20th centuries, this Suillus succeeded in populating other habitats (aspen, mixed woods of yellow birch and hemlocks, etc.)."


Ecology: Apparently mycorrhizal with quaking aspen and big-toothed aspen, as well as eastern white pine; occasionally reported under scrub oak; growing alone, scattered, or gregariously; summer and fall; northeastern North America.

Cap: 3-17 cm; convex becoming broadly convex or flat; slimy and yellow underneath scattered brownish to reddish, appressed fibers and down; often developing a reddish-spotted or streaked appearance; when young with a cottony to felty roll of marginal tissue that sometimes persists into maturity as an inrolled sterile margin. The cap stains waxed paper bright yellow.

Pore Surface: Pale orange to orange or yellowish; not bruising; pores angular and radially arranged, about 2 per mm across; tubes to 1 cm deep.

Stem: 4-8 cm long; 1-2 cm thick; more or less equal; sticky when young; yellowish, discoloring brownish on handling; by maturity with visible brownish glandular dots; without a ring.

Flesh: Yellow; not staining on exposure, or staining pinkish to reddish.

Odor and Taste: Not distinctive.

Chemical Reactions: Ammonia on cap surface olive to red or pinkish; on flesh reddish to pinkish. KOH negative to bluish on cap surface; pinkish, grayish, or purplish on flesh. Iron salts negative on cap surface; olive to negative on flesh.

Spore Print: Olive brown.

Microscopic Features: Spores 7-10 x 3-4 µ; smooth; subfusoid.

REFERENCES: (Peck, 1886) Snell, 1944. (Coker & Beers, 1943; Smith & Thiers, 1964; Snell & Dick, 1970; Smith & Thiers, 1971; Grund & Harrison, 1976; Smith, Smith & Weber, 1981; Phillips, 1991/2005; Both, 1993; Bessette, Roody & Bessette, 2000.) Herb. Kuo 09110407, 09120406, 09120704, 09120705.

This site contains no information about the edibility or toxicity of mushrooms.


Suillus subaureus

Suillus subaureus

Suillus subaureus

Suillus subaureus

© MushroomExpert.Com

Cite this page as:

Kuo, M. (2007, December). Suillus subaureus. Retrieved from the MushroomExpert.Com Web site: