LECCINUM INSIGNE var. BRUNNEUM Thiers, Mycologia 63:272. 1971

Illustrations: See Microfiche No. 32

Pileus 10-15 cm broad, convex, becoming broadly convex to plano-convex; surface dry, dull, glabrous to obscurely velutinous on the margin when young, unchanging or becoming finely and obscurely appressed-fibrillose when older, occasionally finely areolate in some areas with age; color when young brown ("Mars brown" to "Prout's brown" to "walnut brown" to "Rood's brown"), fading to reddish brown ("hazel" to "tawny" to "Kaiser brown" to "russet") at maturity; margin incurved, with conspicuous sterile cuticular flaps. Context 1.5-3 cm thick, white when first exposed, changing to fuscous with no intermediate reddish stage. Taste and odor mild.

Tubes 1-3 cm long, deeply depressed, pale olive ("pale olive-buff"), staining vinaceous to purple, then eventually becoming fuscous when bruised, not becoming brown; pores up to 1 mm broad, often slightly darker olive ("olive-buff" to "dark olive-buff") than the tubes, when older with numerous dark olive ("olive-green") spots.

Stipe 10-15 cm long, 2-2.5 cm thick at the apex, clavate, solid; surface dry, squamulose, ground color white or whitish, squamules pallid when young, becoming black and conspicuous with age. Context white, undergoing similar color changes as in the pileus, not changing to blue.

Spore print brown. Spores 14-16.5 X 5-6.5 Ám, subfusoid to subcylindric, inequilateral, pale ochraceous in KOH, ochraceous in Melzer's, walls smooth, thin.

Basidia 30-35 X 8-10 Ám, subclavate to clavate, four-spored, hyaline. Hymenial cystidia 40-60 X 8-15 Ám, hyaline in KOH, common, inconspicuous, fusoid-ventricose, thin-walled.

Tube trama divergent, hyaline in KOH, hyphae 4-7 Ám wide. Pileus trama interwoven, homogeneous, hyphae 11-15 Ám wide. Pileus cuticle differentiated as a trichodermium of tangled hyphal tips, cells somewhat sausage-shaped, disarticulating, walls smooth to finely asperulate, pigment globules not formed in Melzer's, terminal cells not strongly differentiated, up to 14 Ám broad. Caulocystidia 25-40 X 9-15 Ám, clavate, dark brown in KOH, some large cells interspersed. Clamp connections absent.

Chemical reactions No distinctive reactions observed.

Habit, habitat, and distribution Scattered to gregarious in humus under aspens. Known only from near Devil's Post Pile National Monument.

Material studied Madera County: Thiers 23609, 23610.

Observations The dark-brown pileus when young with a tendency to fade somewhat with age and the dull, dark-brown color when dried readily distinguish this variety from others that have been described.

Edibility undetermined.

The Boletes of California
Copyright © 1975 by Dr. Harry D. Thiers
Additional content for the online edition © 1998 by Michael Wood, Fred Stevens, & Michael Boom
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