LECCINUM CALIFORNICUM Thiers, Mycologia 63:273. 1971

Pileus 5-7.5 cm broad, globose to convex when young, becoming plane to plano-convex when mature; surface smooth, glabrous when young, somewhat fibrillose and often strongly rimose-areolate with age; color almost white to pale buff ("pale pinkish buff" to "pale olive-buff") with age, sometimes darkening to buff color ("pinkish buff" to "vinaceous-buff"); margin entire, lacking sterile cuticular flaps. Context 1-2 cm thick, white, unchanging when exposed. Taste and odor mild.

Tubes 1-1.5 cm in length, depressed, white to pale buff ("pale olive-buff") when young, darkening to olive brown ("olive-buff") and eventually becoming lavender brown ("avellaneous" to "vinaceous-buff" to "wood brown"), becoming dark brown when bruised; pores up to 1 mm broad, angular, concolorous.

Stipe 5-8 cm long, 1-1.5 cm thick at the apex, equal to subclavate; surface dry, grayish yellow in basal region, otherwise white to whitish, squamulose, squamules white to pallid, remaining so or darkening somewhat when very old; solid. Context white, unchanging or becoming yellowish in the base.

Spore print brown. Spores 14.5-17.5 X 5.5-6.5 µm, dark ochraceous in KOH, rarely dextrinoid in Melzer's, fusoid to subcylindric, inequilateral, walls smooth, moderately thick.

Basidia 32-37 X 9-12 µm, hyaline in KOH, four-spored, clavate to pyriform. Hymenial cystidia 45-55 X 7-10 µm, inconspicuous, scattered to rare, fusoid to clavate with elongated, tapering apices, hyaline, very thin-walled.

Tube trama obscurely divergent, hyaline in KOH, hyphae 4-6 µm wide. Pileus trama interwoven, homogeneous, hyphae 8-12 µm wide. Pileus cuticle differentiated as a tangled trichodermium of free hyphal tips, bright red in Melzer's, almost hyaline in KOH, hyphae 7-10 µm wide, some disarticulation noted, no pigment globules developing when mounted in Melzer's, terminal cells slightly narrowed. Caulocystidia 40-55 X 10-17 µm, bright red ("russet") in Melzer's, clavate to mucronate. Clamp connections absent.

Chemical reactions No distinctive reactions observed.

Habit, habitat, and distribution Gregarious in soil under aspens at Grass Lake, Luther Pass, El Dorado County. Known only from the type locality.

Material studied El Dorado County: Thiers 23624.

Observations This species can be distinguished from L. holopus, to which it appears most similar, by the reddish discoloration of the caulocystidia when mounted in Melzer's and the considerably larger cystidia. Also, L. holopus has a greenish cast in the pileus and the flesh changes color when exposed, but L. californicum shows neither of these characteristics. The white to pallid color of the pileus of L. californicum readily distinguishes it from L. montanum, which occurs in the same area.

Edibility not determined.