Leccinum scabrum (Bull.) Gray
common scaber-stalk

Species account author: Ian Gibson.
Extracted from Matchmaker: Mushrooms of the Pacific Northwest.

Introduction to the Macrofungi


© May Kald     (Photo ID #32563)


E-Flora BC Static Map

Distribution of Leccinum scabrum
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Species Information

Features include 1) dingy brownish bald cap, 2) white flesh that may turn brownish, or in stem base blue, 3) whitish pores that darken but do not turn blue, 4) whitish stem with dark brown to black scabers, and 5) growth under birch. Leccinum scabrum was probably introduced with planted birches but does occur with natural birches, for example in northern ID and WA, (Trudell).
Chemical Reactions:
cap cuticle stains reddish brown with application of KOH, bluish slate with FeSO4; flesh reddish-brown with application of KOH, bluish slate with FeSO4, (Bessette)
mild (Bessette, Smith)
mild (Bessette, Smith)
spores 15-19 x 5-7 microns, subfusiform [somewhat spindle-shaped], smooth, pale tawny; cap cuticle end cells "typically uniform and parallel, not inflated and clavate to subglobose"; caulocystidia "mostly clavate with dull ochraceous content in KOH", (Bessette), spores 15-19 x 5-7 microns, subfusiform, smooth, pale tawny in Melzer''s reagent, when revived in KOH pale tawny singly and darker in groups, wall thickened to about 0.5 microns revived in KOH; basidia 4-spored, 11-13 microns wide, colorless in KOH and yellowish in Melzer''s reagent; pleurocystidia none; cap cuticle "a tangled layer of floccose hyphae 6-12(15) microns wide, above a subgelatinous subcutis, their content smoky ochraceous in KOH and with a grayer shadow in Melzer''s but content remaining granular to homogeneous", wall at first enveloped in outer gelatinous matrix that dissolves slowly in KOH, at times a few short slightly inflated cells seen; caulocystidia mostly clavate, 32-46 x 9-17 microns, with smoky ochraceous content in KOH, some clavate-mucronate, and a few varying to fusoid-ventricose; clamp connections absent, (Smith)
Spore Deposit:
brown (Bessette), olive-buff (Miller)
L. scabrum has been found in eastern Canada south to GA, west to AK and CA, (Bessette), BC (Bandoni), WA and OR, (numerous observers), ID (A. Parker, pers. comm.), MI (Smith), NS (Grund), and also Europe (Breitenbach).
yes (Bessette)

Habitat and Range

Leccinum brunneum of California and probably Idaho grows with aspen, and has a dark brown cap that fades to paler brown when old and does not stain blue, whitish stem with whitish scabers that darken when old, and white flesh that stains fuscous without an intervening reddish stage, (Bessette). Leccinum alaskanum in Alaska grows with birch but has a dark brown mottled cap (Bessette). See also SIMILAR section of Leccinum rotundifoliae.
single, scattered or in groups on ground under hardwoods, especially birch, (Bessette), under birch (Smith), summer and fall (Miller), common in urban and suburban settings and less so in natural habitats, (Trudell)


Synonyms and Alternate Names:
Suillus helenae Thiers and A.H. Sm. Mycologia 2.70833333333333 1375-1377.
Suillus umbonatus E.A. Dick & Snell Mycologia 52(3):