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

Summary:
Features include dark purplish gray cap that fades to brownish, a non-separable pore surface that is purplish gray to avellaneous or olivaceous when old, a lateral to central brown to olivaceous reticulate stem, growth on ground, and spores that have a double layered wall with pillars or partitions between the walls. |Polyporoletus sublividus was described from Tennessee in Snell(4). This name has been used for years in the Pacific Northwest based on Gilbertson(1). But Luther(3) summarizes a taxonomic uncertainty, "The original (type) collection for Polyporoletus sylvestris was found near Lake Cowichan, Vancouver Island, BC (Canada) in 1929. Polyporus sylvestris was invalidly published by Overholts (1941), who failed to provide a Latin description. Pouzar (1972) described it correctly and transferred it to Albatrellus as A. sylvestris Overholts ex Pouzar. It was listed as a synonym of P. sublividus by Gilbertson & Ryvarden (1986), but the current research by Audet (2010) provides evidence that it is a distinct species, which he transfers to Polyporoletus as P. sylvestris (Overh. ex Pouzar) Audet." |Audet(1) gives a chart differentiating the features of Polyporoletus sublividus and Polyporoletus sylvestris. In addition, Audet(1) describes the new species Polyporoletus bulbosus based on a WA specimen collected by A.H. Smith (30718 in 1948) In his key, Audet separates Polyporoletus bulbosus and P. sylvestris from Polyporoletus sublividus sensu lato on the basis of spore width: about 7.2-10.8 microns for the first two and 9.6-12.6 microns for the third taxon (spores for the holotype of P. sublividus (9)10.2-12 microns wide). Polyporoletus bulbosus is then separated from P. sylvestris on the basis of solitary habit and bulbous stem in the former and cespitose habit and non-bulbous stem in the latter. (Audet(1)). |Interestingly the description of Polyporus sylvestris in the original paper by Overholts involves not only the type but a second A.H. Smith collection (3189 in 1935): "Unfortunately the type collection was unaccompanied by notes descriptive of their fresh condition. That collection was turned over to Dr. Mounce at Ottawa who assisted in the diagnosis. Good notes by Smith on fresh condition of his plants have been incorporated here also." (Overholts(3)). |Overholts also described Polyporus canaliculatus from North Carolina and Tennessee (an invalid name because of an earlier homonym) which was synonymized by Lowe with Polyporus sylvestris. Spores were 8-12 x 8-10 microns, and the fruitbody was single with stem equal or tapering upward (Overholts(2)).

The range of Polyporoletus sublividus is given by Gilbertson(1) as WA, ID, NC, and TN, (Gilbertson), and the holotype of Polyporus sylvestris is from BC. Ginns(28) says that Polyporus sylvestris is known from BC, WA, OR, and ID.

Cap:
up to 18cm across and 2.5cm thick, circular to kidney-shaped or lobed; dark purplish gray, fading to cinnamon buff to olivaceous tawny, not zoned, in some specimens almost black after drying; tomentose to fibrillose, in some specimens with fibrils becoming appressed in a reticulate pattern, in others bald, (Gilbertson), 5cm across, nearly flat; livid olive, reddish purple on the margin; tomentose on the margin, fibrillose elsewhere, nearly bald on disc, (Snell)

Flesh:
up to 1.5cm thick, soft and friable; not zoned, pinkish buff to ochraceous salmon, (Gilbertson), fruitbody firm and corky; flesh "pale bluish or violaceous, more reddish-purplish under the cuticle"; in stem spongy, colored like cap flesh, (Snell), flesh is speckled with darker spots, like Oreo cookie crumbs in mild (N. Siegel, Facebook)

Pores:
1-2 per mm, circular to angular, with thick walls that become thin and torn when old, decurrent; purplish gray to avellaneous or olivaceous when old; tube layer up to 1cm thick, sharply distinct from flesh but not separable, inner surface of tubes pinkish buff, tissue between the tubes darker, (Gilbertson), pores large, irregular or more or less uneven, tubes very short, 0.1-0.2cm long, "hardly if at all separable, long-decurrent, at first yellow or ochraceous, later brownish with a purplish tinge", (Snell), gray pores that flash different colors when you move it back and forth (N. Siegel, Facebook)

Stem:
up to 10cm x 4cm, lateral to central, cylindric with a bulbous base up to 5.5cm wide; wood brown to olivaceous; reticulate [with net-like pattern], tomentose to finely hispid [bristly], (Gilbertson), 4cm long, 1.8-2.5cm thick, eccentric [off-center], almost lateral; "livid to violaceous-purplish, covered with a yellowish-olivaceous velvetiness in places"; basically nearly bald, coarsely reticulate from walls of tubes, in part to base of stem, (Snell)

Taste:
pleasant (Snell)

Microscopic:
spores 10-12 x 8-10 microns, nearly round to broadly elliptic, "appearing slightly rough, with a double wall separated by interwall pillars or partitions", "outer walls and pillars apparently sloughing off some spores which appear smooth and single walled", inamyloid, colorless, with a large spherical droplet; basidia 2-4-spored, 30-45 x 11-14 microns, clavate, with basal clamp; cystidia none; hyphae monomitic, hyphae of context of 2 types, mostly the first, 1) 5-10 microns wide, colorless, "mostly thin-walled, with clamps and simple septa, with occasionally branching", 2) larger, up to 15 microns wide, unevenly thickened walls; hyphae of trama 2.5-5 microns wide, thin-walled, with clamp connections, also some gloeoplerous hyphae in trama; large globules of dark brown material exude from all tissues, (Gilbertson), spores 7-10 microns in diameter, round, colorless, minutely short-verrucose or echinulate; cystidia scarce, 35-40 x 8-10 microns, clavate, a few slightly rostrate, colorless, (Snell)