Pileus 8-15 cm broad when mature, convex to broadly convex when young, becoming plano-convex to plane at maturity; surface viscid to glutinous, glabrous, occasionally with patches of white veil fragments near the margin, often appearing streaked under the gluten; color dark yellow brown ("buckthorn brown" to "clay color"), becoming darker brown ("cinnamon-brown" to "Prout's brown") with age; margin incurved, becoming broadly decurved with age, often appendiculate from partial-veil fragments. Context 1-2 cm thick, white to pale yellow, unchanging when exposed. Taste and odor not distinctive.
Tubes 0.5-1 cm long, adnexed to arcuate-decurrent to decurrent, yellow ("naphthalene yellow" to "baryta yellow") when young, becoming dark yellow ("old gold" to "colonial buff") when older, unchanging when exposed; pores small, ▒0.5 mm, angular, concolorous with tubes, unchanging when bruised.
Stipe 3-6 cm long, 1-2 cm thick, equal or tapering toward the base, solid; surface dry, white to pallid when young, typically becoming yellow with age, when young appearing glabrous with only obscure glandulae, with age glandulae often become brown and much more conspicuous; annulus distinct, median, fibrillose, sometimes sheathing lower portion of stipe, pallid or pale brownish lavender ("avellaneous"). Context white to whitish, unchanging when exposed.
Spore print pale brown. Spores 7-9 X 2.5-3.5 Ám, hyaline to pale ochraceous in KOH and Melzer's, ellipsoid to subcylindric in face view, slightly inequilateral in side view, smooth, thin-walled.
Basidia 15-21 X 6-9 Ám, clavate, four-spored, hyaline in KOH. Hymenial cystidia 21-35 X 7-10 Ám, scattered, more abundant near the pores, clustered, hyaline, staining dark brown in KOH, clavate to subcylindric.
Tube trama gelatinous in KOH, hyaline, divergent. Pileus trama homogeneous, interwoven. Pileus cuticle differentiated as a tangled ixotrichodermiurn of narrow hyphae, 3-6 Ám wide. Stipe cuticle interwoven, caulocystidia similar to those in the hymenium. Clamp connections absent.
Chemical reactions unknown.
Habit, habitat, and distribution Scattered to solitary in humus, usually under beach or lodgepole pines. Although this fungus is apparently very rare within the state, collections have been made in both the coastal and Sierra Mountain ranges.
Material studied Madera County: Thiers 20899. San Bernardino County: Thiers 24875. Santa Cruz County: Thiers 21703. Tuolumne County: Thiers 21304.
Observations This very interesting species appears rather closely related to several different groups of Suilli. The poorly developed, inconspicuous glandulae on the stipe suggest an affinity with S. brevipes; however, the presence of the annulus makes it distinct. Suillus albidipes and S. glandulosipes also have a partial veil, but the veil remnants adhere to the pileus margin rather than to the stipe as in S. pseudobrevipes. Furthermore, the pileus of S. pseudobrevipes is usually quite dark reddish brown in color, and no pallid or white stage of the basidiocarps is known. Suillus luteus might also be confused with this species, but can be separated by its distinctly glandulose stipe and usually well developed annulus, with a lavender or purple layer or band on the outer surface.
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
A MykoWeb Page