Photo: © Steve Trudell
Boletus edulis
Bull. ex Fr.

Pileus: 4 - 10 cm broad; convex when young, becoming plano-convex when mature; margins inrolled at first becoming straight and even when mature, often exceeding tubes with aging; surface moist to viscid when wet, polished, smooth, at times cracking; pale brown to pale yellow, orange brown when young, becoming darker brown when mature; context 1 - 3 cm at junction of stipe, thick, firm, fleshy, white to pallid, unchanging; taste mild; odour indistinct.

Tubes: Ascending to horizontal when young, becoming free when mature; when young appearing as if the tubes are enclosed in a film of white membranous tissue; tubes are ventricose, wider towards the stipe and narrower towards the margin; colour white and pallid at first, then greyish yellow when mature, unchanging or occasionally turning brown when bruised; pores very small and crowded (2 pores per mm).

Stipe: 5.0 - 12 cm long X 1.0 - 2.5 cm wide apex, 3.0 - 7.0 cm wide at base; with a bulb when young, then obviously club shaped (tapering upwards) sometimes becoming equal when mature, surface dry to moist, unpolished, with white to pallid coloured net-like reticulations towards the apex, smooth towards the base; colours white at first, then greyish yellow to olive brown towards base and when aging; context solid, white to pallid unchanging when bruised, firm.

Microcharacteristics: Spore print olive brown; spores 14 - 18 X 5 - 6 µm narrowly ellipsoid, smooth; hymenial cystidia rare, ventricose fusoid when present.

Comments: This species is solitary to scattered to gregarious in habit. It is not common in these forests, but it fruits consistently in the same location year after year. It can be very large, however, collections found in these forests tend to be smaller and not very robust.

Further Reading:

Dick, E.A. and W.H. Snell: 1968. Some Boleti from Alaska. Mycol. 60: 1204 – 1210.

Thiers, H. D. 1975. California Mushrooms: A field guide to the Boletes. Hafner Press. pp.261.