E-Flora BC: Electronic Atlas of the Flora of British Columbia

Summary:
Features include a well-defined cap and stem, colors of various gray tones, often wavy or lobed cap margin, small white pores that soon discolor, growth on the ground, and angular-warty spores. |We include in Boletopsis grisea group at least the species Boletopsis grisea which is generally a pine associate, and Boletopsis leucomelaena which is generally a spruce associate, but there may be other species as discussed below. The species concepts will likely change with further research. |Gilbertson(1) uses the name Boletopsis subsquamosa. The same authors in 1993 considered the type of P. subsquamosus as probably not a species of Boletopsis at all, and Boletopsis leucomelaena a rare circumboreal species. The name Boletopsis grisea (Peck) Bondartsev & Singer is available, but there are further complications. Analysis of DNA sequences from three Oregon collections showed two to be consistent with Boletopsis grisea and the third from unknown habitat showing some molecular affinity to the newly described pine associate Boletopsis perplexa Watl. & Milne from Scotland (the latter species close to Boletopsis leucomelaena which is a spruce associate and according to the authors'' observations found in the Pacific Northwest but not among the sequenced collections). In the same study a fourth collection from Wind River (from WA) appeared to be another unidentified sequence. (Watling). |Trudell(4) say, "Current thought suggests that at least three species could occur in the PNW. Our commonest one seems to be B. grisea (= B. subsquamosa), which apparently occurs mostly with pine; it has a dull gray to blackish, often radially streaked, cap that sometimes is slightly scaly near the center. The similar B. leucomelaena occurs mainly with spruce. Boletopsis smithii is known from a single collection in Washington and is distinctive by the orange coloration of the cap and stipe." (Trudell, Latin names italicized). |Boletopsis smithii is not considered a member of the Boletopsis grisea group in this program. |Siegel(2) describe Boletopsis grisea and Boletopsis leucomelaena as follows, with Latin names italicized, "B. grisea appears to be limited to pine forest and has whitish to pale gray colors when young, developing darker streaks and stains in age. B. leucomelaena has a black cap, white to light gray pores, and a gray stipe (often with an orangish base), and grows with spruce."

Members of this group are found in BC, WA, OR, ID, also NS, AL, CA, GA, MA, MI, MO, MT, NC, NH, NJ, NY, PA, TN, and VA.

Cap:
4-15(20)cm, broadly convex to flat or slightly depressed, circular to somewhat irregular, margin incurved at first, often wavy or lobed; "dingy whitish to gray, purple-gray, bluish-gray, vinaceous-tinged, or with olive, pinkish, brownish, or even black tones (usually darker in age), often with a somewhat streaked appearance"; dry, smooth to fibrillose or breaking into fine scales especially centrally, (Arora), up to 15cm wide, often irregular in outline with thin wavy margin, fleshy when fresh, soft to brittle when dry, annual; dull gray to sordid brown with olivaceous tinges, not zoned; smooth to scaly, slightly wrinkled when dry, (Gilbertson)

Flesh:
thick, firm; white or tinged with cap colors, (Arora), up to 3cm thick, white when fresh, darkens when touched in fresh condition, becoming greenish gray when dry, (Gilbertson)

Pores:
1-5 per mm, "usually white when fresh and young but soon discolored grayish, vinaceous-buff, brownish, etc."; tubes 0.2-0.4cm long, usually at least somewhat decurrent, (Arora), 1-3 per mm, decurrent on stem, angular, thin-walled; white drying pale grayish; tube layer up to 0.8cm thick, usually distinctly paler than flesh, (Gilbertson)

Stem:
(2)4-13cm x 1-4cm, central or off-center, equal or with narrowed base, solid; whitish or colored like cap or pores; smooth, (Arora), up to 7cm long and 3cm wide, central or lateral, fleshy when fresh; gray to pale sordid olivaceous brown; smooth to finely scaly with darkened scales, wrinkled when dry, (Gilbertson)

Odor:
insignificant (Lincoff(1))

Taste:
mild to bitter (Arora), weak when fresh, sweetish to spicy when dry, (Gilbertson)

Microscopic:
spores 4-7 x 3.5-5 microns, elliptic to nearly round but distinctly angular-warty, (Arora); spores 5-7 x 4-5 microns, angular and irregular in outline, inamyloid, colorless to pale brownish; basidia up to 43 microns long and 10 microns wide, with 4 large sterigmata and a basal clamp, "pleurobasidial or clavate, arising from horizontal hyphae in the subhymenium partly as swollen enlargements on the hyphae, partly with irregular outline"; hyphal system monomitic: generative hyphae of variable diameter (3-20 microns), delicately thin-walled to slightly thick-walled (in the subhymenium), colorless, branching irregular, clamp connections at all septa, (Gilbertson)

Spore Deposit:
white to pale brown (Arora)