LECCINUM LARGENTII sp. nov.

Illustrations: See Microfiche No. 33

Pileus 8-15 cm latus, convexus vel plano-convexus, siccus interdum viscidus aetate, appresso-fibrillosus vel fibrilloso-squamosus margine, disco tomentosus vel velutinus, obscure rufus. Contextus albus tactu fuscus. Tubuli 1-2 cm longi, fusco-olivacei; pori fumoso-brunnei. Stipes 10-12 cm longus, 1.5-3.5 cm latus, siccus, albus, squamis confertis, fuscis, parvulis. Sporae 13.3-17.1 X 4-6 Ám, subcylindricae vel subellipsoideae. Cuticula intertexta, globulis pigmenti (in Melzer's). Holotypus (no. 28531) a David Largent lectus prope Eureka, Humboldt County, October 30, 1971; in Herbarium San Francisco State University conservatus.

Pileus 8-15 cm broad, convex when young, becoming broadly convex to pulvinate to plano-convex to somewhat irregular at maturity; surface dry, becoming subviscid to viscid only when wet or very old, appressed fibrillose to appressed fibrillose-scaly, sometimes conspicuously so near the margin, innately fibrillose to tomentose to velutinous on the disc, sometimes appearing somewhat glabrous on the disc with age, some often obscurely and shallowly areolate when very old; color deep, dark reddish brown ("bay" to "mahogany red" to "claret brown") to pale reddish brown ("chestnut" to "auburn"), near the margin sometimes slightly paler-red to orange red ("apricot orange" to "scarlet"); margin incurved, with very dark colored sterile flaps or sterile margin entire and not becoming broken into flaps. Context 1-3 cm thick, white, slowly and erratically becoming directly fuscous when exposed, most conspicuous and often only change occurring at the juncture of stipe and pileus, change much more pronounced than in L. manzanitae. Taste and odor mild.

Tubes 1-2 cm long, shallowly depressed; color pale olive ("olive-buff" to "pale olive-buff"); pores small, less than 1 mm broad, angular in outline, smoke colored ("dark olive-buff" to "citrine-drab"), unchanging or becoming dark olivaceous ("Saccardo's umber" to "deep olive") with age, staining deep olive when bruised.

Stipe 10-12 cm long, 1.5-3.5 cm thick, ventricose to tapering toward the base, solid; surface dry, covered with very fine, densely packed squamules colored pale brown ("clay color"), with age becoming dark brown to black, but remaining small and dense; in some, the surface becomes reticulate to almost alveolate from the elaboration of the squamules; background color white during all stages. Context white, changing to fuscous at the apex, often with a reddish or bluish discoloration at the base.

Spore print color not determined. Spores 13.3-17.1 X 4-6 Ám, pale ochraceous in KOH and Melzer's, subcylindric to subellipsoid, inequilateral, walls smooth, moderately thick.

Basidia 26-34 X 7-10 Ám, clavate to pyriform, hyaline in KOH and Melzer's, four-spored. Hymenial cystidia 21-28 X 5-7 Ám, scattered to rare, embedded, hyaline, very thin-walled, inconspicuous, fusoid to somewhat fusoid-ventricose with an elongated, narrowed apex.

Tube trama slightly divergent from a central strand, hyaline in KOH, hyphae 5-7 Ám wide. Pileus trama hyaline in KOH, interwoven, homogeneous, hyphae 6-9 Ám wide. Pileus cuticle differentiated as a tangled trichodermium, terminal cells tapered noticeably at the apex, considerable disarticulation of the hyphal cells, hyphae 7-9 Ám wide, walls smooth, contents ochraceous to cinnamon in KOH, pigment globules developing when mounted in Melzer's. Caulocystidia 40-55 X 12-20 Ám, clavate, thin-walled, cinnamon to ochraceous in KOH, bright rust ochraceous in Melzer's. Clamp connections absent.

Chemical reactions FeSO4-context pale gray, pores very dark olive; guiaic-weakly positive on context in base of stipe.

Habit, habitat, and distribution Gregarious to scattered under toyon (Heteromeles arbutifolia). Known only from the vicinity of Samoa near Eureka.

Material studied Humboldt County: Thiers 28531 type. (Collection made by David Largent.)

Observations This is another of the large, massive boletes found associated with hardwoods in the coastal forests of northern California and is apparently related to L. manzanitae. Leccinum largentii, however, has a dry pileus that is often noticeably appressed fibrillose-scaly on the margin, very dark smoky olive pores that do not change color with age, and a highly distinctive elaboration of the squamules on the stipe. The last character is perhaps the most distinctive of all. This species is somewhat suggestive of L. fallax, which occurs in the Rocky Mountains under spruce and fir, has narrower spores, and pallid squamules on the stipe.

Edibility unknown.

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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