LECCINUM CONSTANS sp. nov.

Illustrations: See Microfiche No. 29

Pileus 10-14 cm latus, uvidus vel subviscidus, glaber in centro, appresso-fibrillosus ad marginem, subpuniceus, fibrillulis parce furvioribus. Contextus 2.5 cm crassus, albus, immutabilis. Tubuli 2 cm longi, albi demum subolivacei; pori 1 mm lati, concolores tactu brunnei. Stipes 12-15 cm longus, 2-3 cm crassus, siccus, fibrilloso-squamosus, albus, squamis fuscis; contextus albus, immutabilis. Sporae 15.5-18 X 4-5 Ám, fusoideae vel subellipsoideae. Cystidia 24-31 X 7-9 Ám, inconspicua, fusoidea vel submucronata. Cuticula intertexta, globulis pigmenti nullis (in Melzer's). Holotypus (no. 26971) a H. D. Thiers lectus prope Boulder Creek, Santa Cruz County, December 6, 1970; in Herbarium San Francisco State University conservatus.

Pileus 10-14 cm broad when mature, convex to pulvinate during all stages of development; surface moist to subviscid, more or less glabrous on the disc, becoming closely appressed fibrillose toward the margin; ground color pale pink ("pinkish buff" to "pale pinkish buff"), fibrils somewhat darker ("apricot buff" to "flesh ocher" to "ochraceous-salmon"); margin with sterile flaps of cuticular tissue. Context up to 2.5 cm thick, white, unchanging when exposed.

Tubes up to 2 cm in length, white to whitish when young, changing to pale olive ("olive-buff") when bruised; pores less than 1 mm broad, angular, concolorous, staining brown when bruised.

Stipe 12-15 cm long, 2-3 cm thick at the apex, clavate to subclavate, solid; surface dry, densely squamulose or furfuraceous, ground color white, squamules whitish to pale brown when young, becoming dark brown with maturity. Context white, unchanging in any portion when exposed.

Spore print unknown. Spores 15.5-18 X 4-5 Ám, fusoid to subellipsoid in face view, inequilateral in profile, pale ochraceous in Melzer's and KOH, walls smooth, moderately thick.

Basidia 25-31 X 6-9 Ám, hyaline in KOH, four-spored, occasionally one to two-spored, clavate. Hymenial cystidia 24-31 X 7-9 Ám rare, inconspicuous, hyaline, thin-walled, fusoid to submucronate.

Tube trama hyaline, divergent, hyphae 5-6 Ám wide. Pileus trama hyaline, interwoven, homogeneous. Pileus cuticle differentiated as a tangled trichodermium of septate hyphal tips, considerable disarticulation of cells, terminal cell not differentiated, cell walls sometimes asperulate, pigment globules not formed in Melzer's. Scales on stipe composed of clavate caulocystidia that stain brown in KOH. Clamp connections absent.

Chemical reactions unknown.

Habit, habitat, and distribution Solitary in soil in dense hardwood coastal forests near Santa Cruz.

Material studied Santa Cruz County: Thiers 26971 type.

Observations This is another species of Leccinum apparently associated with madrone. Although similar in gross appearance to L. manzanitae, L. constans is easily distinguished by the absence of a viscid pileus, the noticeably paler color of the pileus, and, most significantly, the absence of any color change in the context of either the pileus or stipe. This species belongs to the subsection Vulpina of the section Leccinum, but it is difficult to predict its affinities within that section.

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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