|Major Groups > Boletes > Suillus > Suillus sibiricus|
by Michael Kuo
Suillus sibiricus was originally described from Siberia by Rolf Singer (1938)--and the name has since been variously applied by mycologists across the globe. In North America, "Suillus sibiricus" usually refers to the western equivalent of Suillus americanus, but it is unclear whether this western mushroom is actually distinct from Suillus americanus, or whether it actually corresponds to Singer's Siberian mushroom.
Both Suillus sibiricus and Suillus americanus are associated with 5-needle pines, and physical differences are not significant. Some authors attempt to separate the two mushrooms on the basis of the width of the stem (to 1.5 cm in Suillus sibiricus, but only to
If you ask me (you certainly don't have to) the two species, if they are distinct, are so by virtue of their mycorrhizal associations and range, rather than imagined differences in physical features. Suillus americanus associates with Pinus strobus; Suillus sibiricus associates with Pinus monticola and Pinus flexilis. Reports of Suillus sibiricus in eastern North America probably represent Suillus americanus, and rely on a second-hand account from Snell & Dick (1970; "reported from a tamarack bog in Ontario") and a single identification from Smith & Thiers (1971; "known in Michigan from the Yankee Springs Recreation Area in Barry County"), and probably result from over-emphasis of differences in morphological features that are, ultimately, variable (the same applies to reports of Suillus americanus from the Southwest).
Cap: 3-10 cm; convex becoming broadly convex or flat, sometimes with a broad central bump; sticky to slimy; dull to bright yellow; smooth or, more commonly, with scattered brownish to reddish brown fibers, streaks, scales, or patches; usually with partial veil remnants on the margin.
Pore Surface: Yellow becoming brownish yellow; usually bruising pinkish to cinnamon; pores angular and radially arranged, 1-2 mm across; tubes to 1.5 cm deep.
Stem: 4-11 cm long; up to 1.5 cm thick; equal; dull to bright yellow underneath brown to reddish brown glandular dots; sometimes with a fragile ring; staining reddish to purplish brown with maturity or on handling, especially toward the base.
Flesh: Yellow; not staining on exposure, or staining pinkish to reddish.
Odor and Taste: Not distinctive.
Chemical Reactions: Ammonia red on cap surface; red on flesh. KOH black on cap surface (sometimes after a red flash); black on flesh. Iron salts negative to grayish on cap surface; grayish to greenish on flesh.
Spore Print: Cinnamon brown.
Microscopic Features: Spores 8-12 x 3.5-4.5 µ; smooth; subfusoid.
REFERENCES: (Singer, 1938) Singer, 1945. (Singer, 1945; Smith & Thiers, 1964; Smith, Thiers & Miller, 1965; Smith & Thiers, 1971; Smith, 1975; Thiers, 1975; Smith, Smith & Weber, 1981; Arora, 1986; States, 1990; Phillips, 1991/2005; Both, 1993; Bessette, Roody & Bessette, 2000.) Herb. Kuo 08150717.
Further Online Information:
Cite this page as:
Kuo, M. (2007, December). Suillus sibiricus. Retrieved from the MushroomExpert.Com Web site: http://www.mushroomexpert.com/suillus_sibiricus.html