Cap 6-15 cm broad, convex expanding to nearly plane in age, the margin at first inrolled, then decurved, often wavy at maturity; surface dry, fibrillose to finely scaled or cracked near the margin, dark-brown at the disc, shading to medium-brown at the margin; flesh white, thick, discoloring slowly brown when injured; odor and taste mild.
Gills close, adnexed to notched, moderately broad, cream to buff, pale drab brown in age, often mottled darker brown at maturity, especially the edges.
Stipe 5-10 cm long, 2-3.5 cm thick, stout, solid, equal, or tapering to a narrow, sometimes rooted base, surface dry, dull, cream-buff at the apex, developing brown stains below; veil absent.
Spores 5.5-7.0 x 4-5 µm, elliptical, smooth; spore print white.
Scattered to gregarious under pines (Pinus), especially Monterey pine (Pinus radiata); fruiting from mid to late winter.
Questionable. Although described as edible by some authors, local experience is lacking. In addition, at least one reddish-brown Tricholoma in our area is known to cause G.I. upsets (see Comments below).
Distinguishing features of Tricholoma imbricatum include a dry, dark-brown, appressed fibrillose to finely scaled cap, cream-buff gills that become mottled brown in age, a stipe that discolors brown except for the apex, and the lack of a strong cucumber odor. Tricholoma muricatum, known to cause G.I. upsets, is similar in appearance but has a viscid (when moist), reddish-brown cap and a distinct cucumber odor. Another relative is Tricholoma vaccinum. It has a dry, reddish-brown, finely scaled cap with a hairy margin when young and a hollow stipe. Of these, Tricholoma imbricatum and T. muricatum are the most likely to be encountered. Fruiting bodies of Tricholoma imbricatum are resistant to decay and like those of Leucopaxillus albissimus, may persist for several weeks.