Boletus pinophilus: Boletus rex-veris

Common Name: Spring King
Misapplied names: Boletus pinophilus Pilat & Dermak; Boletus edulis Fries; Boletus edulis var. pinicola Vittadini; Boletus pinicola (Vittidini) Venturi

Pileus
Cap 9.0-18.0 cm broad, hemispheric to convex, the disc sometimes depressed in age; margin incurved, then decurved to plane, overlapping the pore layer in youth; surface viscid when moist, glabrous with shallow depressions, wrinkles, or pits; at maturity patchy-tomentose or inconspicuously areolate; unexposed color pallid, then flushed pinkish to vinaceous-brown, at times with a silvery-grey bloom, becoming dull reddish-brown with ochre-brown tints, finally date-brown to dull olive-brown, pinkish tones occasionally persisting along the margin; cap darkening where handled; context up to 3.0 cm thick, white, unchanging, firm when young, soft at maturity; odor mild; taste pleasant, slightly sweet.

Hymenphore
Pores at first white, stuffed, then cream-yellow, eventually dingy yellowish-olive to yellowish-brown, not discoloring when bruised, 2-3/mm, mostly rounded in outline, not boletinoid; tubes depressed adjacent to stipe, colored like the pores, up to 1.5 cm long.

Stipe
Stipe 5.0-10.0 cm long, 2.0-6.0 cm thick, the base slightly enlarged to clavate; context solid, white, unchanging; surface dry, cream-colored gradually becoming pale vinaceous-brown, the upper half conspicuously reticulate, the ornamentation at first white, then concolorous with the underlying stipe color; darkening slightly where handled; partial veil absent.

Spores
Spores 12.5-18.0 x 4.0-5.0 µm, narrowly elliptical to spindle-shaped in face-view, similar in profile, but slightly inequilateral, smooth, thin-walled, with numerous vacuoles; spores olive-brown in deposit.

Habitat
In small groups or cespitose clusters under montane conifers, especially pines; fruiting in late spring; common in some years.

Edibility
Edible and very good; best in the button stage; mature specimens usually dried.

Comments
Boletus rex-veris, commonly known as the Spring King, fruits in late May or early June, often just as the morel season is drawing to a close. A relative of Boletus edulis, it is unusual in tending to fruit in clusters, frequently along dirt roads and trails. Despite these features, it is not necessarily an easy find. Like many montane mushrooms, fruitings may occur under a layer of dirt or duff. The cap color of Boletus rex-veris varies considerably with age. Young unexposed caps are nearly white, turning pinkish-tan with a silvery bloom, then drab olive-brown to dark-brown with mustard tints. Boletus rex-veris is a good example of a mushroom well known to mushroom hunters as it is a good edible, like its better known cousin, Boletus edulis. The latter differs in having a more clavate stipe and a brownish cap that lacks pinkish tints when young. Additionally, it rarely occur in clusters, and usually fruits in late summer or fall in the Sierra Nevada or winter in low elevation forests. Two other spring fruiting boletes that occur in montane habitats are Boletus regius and Boletus rubripes. Boletus regius mimics B. rex-veris in having a pinkish tinged cap when young, but the pores are bright yellow and bruise blue. Boletus rubripes is distinguished from B. rex-veris by a stipe that is reddish at the base and yellowish at the apex, lacking reticulations, and pores that bruise blue.
Until recently we used the name Boletus pinophilus for our California material, although it has long been thought that Boletus pinophilus is a similar, but distinct, species from Europe. We now have a correct name to place on our species.