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

Summary:
Features include 1) a viscid to glutinous cap that is orange-brown, becoming vinaceous brown or brownish red to yellow-brown when old, 2) a cap margin with scattered white scales or hanging veil remnants, 3) white flesh that may stain vinaceous, 4) round pores that are buff to yellow or orange buff, 5) dry stem that is yellowish to buff at the top and white in the lower part, the stem sometimes having a few glandular dots, and often having a fleeting ragged annular zone, and 6) growth under conifers especially pine. The holotype of Suillus albivelatus is albivelatus is one substitution and 1 indel different in the ITS region than one of Smith''s original 1964 collections of S. pseudobrevipes, so it may be that they are not separate species (D. Miller, pers. comm.).

Suillus albivelatus is found in the Pacific Northwest and the northern Rocky Mountains, south to ID and northwestern MT, (Bessette). There is a WA collection at the University of Washington. It has also been reported from BC (M. Beug, pers. comm.) and AB (Schalkwijk-Barendsen).

Cap:
4-12cm, convex becoming nearly flat when old; orange-brown on young specimens, becoming vinaceous brown or brownish red to yellow-brown when old; bald, viscid to glutinous; margin with scattered white squamules or appendiculate, (Bessette(3)), 4-12cm, convex to broadly convex; pallid when covered by duff, when exposed soon pale vinaceous brown then slowly changing to dull cinnamon to dull yellow-brown, finally dingy ochraceous; buttons 0.2-1cm wide with a white-fibrillose veil over the glutinous to viscid surface, the veil breaking up into fine fibrillose scales then disappearing, in caps 2.5-8cm wide veil usually visible as white floccose scales over marginal area (or sometimes over all) and the margin toothed with remnants, finally all traces removed, especially in wet weather, when old often virgate (streaked) under the gluten; at times with part of the margin intergrown with stem, (Smith)

Flesh:
white, becoming buff to lemon-yellow when old, especially near tubes, "unchanging or staining vinaceous when cut", (Bessette(3)), white but soon lemon-yellow, staining reddish around larval tunnels; in stem the base staining vinaceous brown from larval damage; "the interior surface and to some extent the exterior becomes vinaceous-lilac to vinaceous-pink" [unclear which part(s) of fruitbody this refers to], (Smith)

Pores:
1-3 per mm, round; buff at first, becoming yellow to orange-buff when mature; tube layer 0.3-0.6cm thick, often depressed near stem when old, (Bessette(3)), round, minute at first, finally up to 1mm when old, colored as tubes (pale ocher-yellow), not changing when bruised; tube layer 0.5-1cm thick, varying from depressed around the stem to decurrent, dull pale ocher-yellow, unchanging when cut, (Smith), pores somewhat boletinoid [radially arranged], (Bessette(1))

Stem:
1-4cm x 1.5-3cm, nearly equal, solid; yellowish to buff at top, white in lower part; dry, smooth or with a few glandular dots usually near top; "sometimes with a ragged annular zone that soon disappears", (Bessette(3)), 1-4cm x 1.5-2.5cm, more or less equal, solid; white and becoming bright yellow, base more or less clay color from handling; lacking dots when young and when old lacking dots or with a few minute dots showing near top; veil at times (about 50%) leaving a poorly formed zone of fine scales midway on the stem, the fine scales whitish or discoloring to vinaceous fawn; reference is also made to the "annulus when present", (Smith)

Chemical Reactions:
KOH on flesh gives pink then lilac-drab reaction, on cap cuticle no reaction, FeSO4 no reaction, (Smith)

Odor:
not distinctive (Bessette(3))

Taste:
not distinctive (Bessette(3))

Microscopic:
spores 7-8.5 x 2.5-3 microns, elliptic, smooth, yellowish, (Bessette(3)), 7-8.5 x 2.8-3 microns, oblong, smooth, yellowish in KOH, only slightly more yellowish brown in Melzer''s reagent; basidia 4-spored, many with red content; pleurocystidia in clusters, 38-50 x 8-12 microns individually, subfusoid, clavate or cylindric, content and area surrounding cluster vinaceous-red in KOH; cap epicutis of hyphae 4-9 microns wide, "appressed on cap surface (possibly a collapsed trichodermium), gelatinous as revived in KOH and with numerous minute granules in the gelatinous matrix, the granules +/- yellowish in KOH and in Melzer''s sol."; caulocystidia in clusters or scattered and similar to pleurocystidia; clamp connections none, (Smith), clamp connections present on all tissues (Bessette(1))

Spore Deposit:
cinnamon-brown to buff (Bessette(3)), near cinnamon-buff after moisture has escaped (Smith)