Cap 5-10 cm broad, convex, expanding to nearly plane, in age the disc sometimes depressed with an uplifted margin; margin inrolled, often wavy, becoming decurved, faintly to not striate, rarely conspicuously striate; surface viscid when moist with appressed, radial fibrils, dark red-brown to dull orange-brown, the margin slightly lighter; flesh thick, firm, white, unchanging; odor, mild or faintly of cucumbers; taste, bitter.
Gills notched to subdecurrent, close, moderately broad, pallid becoming dull-buff, the edges often discoloring brown in age.
Stipe 3-8 cm tall, 1.5-2.5 cm thick, solid, round, equal to tapering to a narrowed base; surface cream-buff at the apex, pruinose to slightly fibrillose-striate; below the annulus scattered dingy-brown fibrils or minute scales over a cream-buff ground color, darkening overall in age; veil of glutinous fibrils leaving scattered remnants in a medial to superior zone, the lower margin of which defined by a thin brown line.
Spores 5.5-7.5 x 4-5.5 µm, elliptical, smooth, non-amyloid; spore print white. According to Shanks, basidia mostly 2-spored.
Gregarious, often clustered, in conifer woods; fruiting from late fall to mid-winter.
Tricholoma fracticum closely resembles T. muricatum (formerly known locally as T. pessundatum). Both species have viscid, reddish-brown caps and are found under pines, particularly Monterey pine (Pinus radiata) in our area. Tricholoma fracticum can be distinguished from T. muricatum by the lack of distinctly ribbed/striate margin, a mild to only faintly cucumber odor and a partial veil that forms a thin annular line on the stipe. Another frequently seen dark-brown Tricholoma that occurs with pine is T. imbricatum. It has a dry, not viscid, appressed fibrillose cap, lacks a veil, and a strong farinaceous odor.