BOLETUS SMITHII Thiers, Mycologia 57:530. 1965

Illustrations: See Microfiche No. 19

Pileus 5-16 cm broad, convex when young, unchanging or becoming broadly convex to plano-convex when mature; surface dry, dull to unpolished, even when young but often with irregular depressions when older, velutinous to tomentose when young, becoming fibrillose to matted-fibrillose with age, sometimes appearing glabrous when very old and often becoming rimose-areolate upon drying or with age; background color olive yellow to buff ("pale olive-buff" to "deep olive-buff" to "tawny-olive" to "Isabella color"), but typically with pinkish or reddish overtones or blotches, when older frequently appearing red ("Pompeian red" to "jasper red") over entire surface or with the olive pigment confined to a narrow zone near the margin, sometimes becoming yellowish near the margin; margin entire, incurved, becoming decurved with age. Context 1-3 cm thick, pale yellow ("pale greenish yellow") except sometimes reddish near the cuticle, unchanging or slowly and erratically changing to blue when exposed, occasionally rapidly bluing. Taste and odor mild.

Tubes 1-1.5 cm long, adnate to arcuate decurrent when young, typically becoming deeply and narrowly depressed with age, yellow ("barium yellow" to "straw yellow") when young, becoming dark yellow ("reed yellow" to "olive-yellow") with age, bluing immediately upon exposure; pores 0.5-1 mm broad, angular, concolorous or sometimes appearing reddish near the margin when old, bluing when bruised.

Stipe 6-16 cm long, 1-3.5 cm thick at the apex, equal to tapering toward the apex or sometimes becoming clavate, solid; surface dry, smooth to granulose or pruinose, occasionally appearing appressed-fibrillose to tomentose, not reticulate; color red ("Eugenia red" to "Pompeian red" to "jasper red") toward the apex, changing to yellow ("naphthalene yellow" to "barium yellow") toward the base; sometimes the color pattern reversed or entirely red or, rarely, entirely yellow, usually with a distinct red band at the apex with age. Context yellow to pallid, bluing when exposed.

Spore print olive brown. Spores 14.5-19.2 X 4-6 Ám, pale ochraceous in KOH, ochraceous to dark ochraceous in Melzer's, smooth, thin-walled, fusoid to subcylindric in face view, ventricose in side view.

Basidia 30-36 X 7-10 Ám, four-spored, hyaline, clavate. Hymenial cystidia 30-60 X 7-12 Ám, typically deeply embedded in the hymenium, sometimes obscure, hyaline, thin-walled, clavate to fusoid to fusoid-ventricose.

Tube trama hyaline to ochraceous in KOH -gelatinous, divergent from an obscure central strand, sometimes with occasional laticiferous hyphae. Pileus trama homogenous, interwoven. Pileus cuticle differentiated as a layer of loosely interwoven, tangled hyphae forming a poorly defined trichodermium, often with free hyphal tips, which appear somewhat cysticlioid and sometimes fasciculate, some hyphae staining ochraceous in KOH, occasionally with numerous laticifers. Stipe cuticle differentiated as a layer of fertile basidia in the upper portion, changing to a layer of interwoven hyphae toward the base. Clamp connections absent.

Chemical reactions KOH-cuticle black; HCl-context pinkish yellow, cuticle pink; HNO3-context pinkish yellow, cuticle reddish; sulfoformalin-context pinkish yellow, cuticle pinkish.

Habit, habitat, and distribution Solitary to gregarious in soil in dense mixed coastal forests. Curiously enough, this species has been found only in the vicinity of Mendocino in California, yet it was first collected in the Cascades in Oregon and has since been found in Washington and Idaho. It apparently fruits only during the fall-winter rainy season.

Material studied Mendocino County: Breckon 39; Motta 270; Thiers 8208, 9305, 9355, 9419, 9812, 10644, 10674, 11872, 14142, 14594, 21315, 21525, 23066, 24183, 24218.

Observations This species presents a very distinctive color pattern in the pileus in which there is a curious mixture of olive-gray, yellow, and red pigments. Most commonly, the background color is olive or olive brown or gray often overlain and sometimes obscured with red or pink overtones. With age, red frequently predominates, and the olive or gray pigments may completely disappear or become confined to a narrow marginal zone. The matted-fibrillose to tomentose or velutinous cuticle, the red band at the stipe apex, and the inconspicuous cystidia are additional distinctive features.

Edibility unknown.

Online edition addendum

Other Descriptions and Photos: The Fungi of California

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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