Pulveroboletus ravenelii

Pileus
Cap 7.0-9.0 (12.0) cm broad, convex, broadly so in age; margin decurved, appendiculate in youth; surface subviscid when moist, otherwise dry, at first covered with a veil of sparse, bright-yellow tomentum which gradually disappears revealing a reddish to orange-brown ground color; context 1.0-1.5 cm thick, soft, cream-colored, unchanging to slowly bluing; odor mild; taste acidic.

Hymenophore
Pores 1-2/mm at maturity, oval to angular, cream-colored when young, aging ochre-brown, bruising blue, sometimes dark-brown when injured; pore layer depressed near the stipe, when young covered with an evanescent, bright-yellow fibrillose veil, leaving fragments toward the margin; tubes up to 1 cm long, bluing when cut.

Stipe
Stipe 4.0-10.0 cm long, 2.5-4.0 cm thick, solid, equal to ventricose, if the latter, then narrowed at the base; apex not reticulate, surface covered by a bright-yellow, fibrillose-tomentose universal veil, underlying surface pallid, longitudinally striate; context yellow, unchanging; pale yellowish mycelium at the base.

Spores
Spores 8.5-12.0 (13.0) x 4.0-5.5 µm, smooth, thin-walled, narrowly elliptical in face-view, subfusoid and slightly inequilateral in profile; hilar appendage inconspicuous; one to several guttules present; spores olive-brown in deposit.

Habitat
Solitary or in small groups in mixed hardwood/conifer woods, Coast Ranges and lower elevations of the Sierra Nevada; fruiting shortly after the fall rains; uncommon.

Edibility
Inedible; unpleasant sour taste.

Comments
Pulverobletus ravenelii is unusual among boletes in possessing a universal veil. Even more remarkable is the florescent-yellow color of the veil which makes young specimens nearly unmistakable. With age and weathering, however, much of the veil disappears except for remnants on the stipe and cap margin. Mature specimens have a reddish-brown tinged cap which can cause confusion with Boletus appendiculatus (Butter Bolete). The latter differs in its larger size and reticulate stipe. Boletus orovillus, a sulfur-colored bolete, is also similar but fruits before the fall rains near conifer stumps and woody debris, and does not develop reddish-brown cap tones.