Leccinum scabrum
Nat. Arr. Brit. Pl. 1: 647. 1821.
Common Name: birch bolete
Cap 5.0-14.0 cm broad, convex, broadly convex in age with a decurved margin; surface when young, dingy-tan, dull, matted-tomentose, subviscid, occasionally areolate; at maturity sometimes weathering glabrous, becoming viscid, medium-brown to dull olive-brown; context soft, up to 1.5 cm thick, cream-colored, unchanging or occasionally faintly pink or blue where cut or injured; odor and taste mild.
Pores cream-buff to pale tan, bruising pale olive-buff, deeply depressed at the stipe; tubes 1-2 cm long, pallid when young, in age pale coco-brown, unchanging when cut or bruised.
Stipe 8.0-14.0 cm long, 2.0-4.0 cm thick, clavate in youth, becoming subclavate to equal at maturity, solid, straight; surface of apex pruinose, pallid to cream, longitudinally ridged below, sometimes forming a coarse reticulum, ornamented with black squamules; partial veil absent.
Spores 14-18 x 5-6 µm, subfusoid to narrowly ellipsoid, smooth, thin-walled with variously-sized vacuolar inclusions; spore print dull brown.
Solitary to scattered under ornamental birch (Betula spp.). fruiting in late summer in watered areas, again shortly after the fall rains.
Edible, of fair quality. Many Leccinums are better after being dried.
Leccinum scabrum is recognized by a dull tan-brown to medium-brown cap that may be subviscid to viscid depending on conditions, and a context that normally does not blue when cut, or if so, only faintly. In California it appears to be restricted to ornamental birches (Betula spp.) planted in urban areas, and presumably was introduced on nursery rootstock. It often fruits with another birch-loving species, Lactarius pubescens var. betulae.
Bessette, A.E., Roody, W.C. & Bessette, A.R. (2000). North American Boletes: A Color Guide to the Fleshy Pored Mushrooms. Syracuse University Press: Syracuse, NY. 400 p.
Breitenbach, J. & Kränzlin, F. (1991). Fungi of Switzerland. Volume 3: Boletes and Agarics (1st Part). Strobilomycetaceae, Boletaceae, Paxillaceae, Gomphidiaceae, Hygrophoraceae, Tricholomataceae, Polyporaceae (lamellate). Verlag Mykologia: Luzern, Switzerland. 361 p.
Desjardin, D.E., Wood, M.G. & Stevens, F.A. (2015). California Mushrooms: The Comprehensive Identification Guide. Timber Press: Portland, OR. 560 p.
Ellis, M.B. & Ellis, J.P. (1990). Fungi without Gills (Hymenomycetes and Gasteromycetes). Chapman and Hall: London, England. 329 p.
Grund, D.W. & Harrison, K.A. (1976). Nova Scotian Boletes. J. Cramer: Vaduz. 283 p.
Knudsen, H. & Vesterholt, J. ed. (2008). Funga Nordica: Agaricoid, boletoid and cyphelloid genera. 965 p.
Knudsen, H. & Vesterholt, J. ed. (2012). Funga Nordica: Agaricoid, boletoid, clavarioid, cyphelloid and gastroid genera. Vol. 1. Nordsvamp: Copenhagen, Denmark. 511 p.
Smith, A.H. & Thiers, H.D. (1971). The Boletes of Michigan. University of Michigan Press: Ann Arbor, MI. 426 p. (PDF)
