Jahnoporus hirtus (Quell.ex.Cke.) Nuss.
Hoppea 39: 176. 1980.

Common Name: none

Synonyms: Polyporus hirtus, Albatrellus hirtus

• Sporocarp

  Fruiting annual, solitary to clustered, fan-shaped or convex, sometimes centrally depressed; margin entire to irregular; surface short pubescent, occasionally furrowed, lilac-brown, grey-brown, to dark-brown; context 0.7-1.5 cm thick, white, fleshy, tough, unchanging; odor mild; taste bitter, often latently bitter.

• Hymenophore

  Pores white to cream, 1-2 per mm, thin-walled, angular at maturity. Tubes 0.3-0.7 cm long, white, decurrent.

• Stipe

  Stipe 4-9 cm long, 2-3.5 cm thick, usually laterally attached, solid, tough, usually tapering downward and extending into the substrate, the radicating portion white with adhering debris; elsewhere the stipe surface like the cap, i.e. dull brown and pubescent.

• Spores

  Spores 10.5-14.0 x 4-5 µm, spindle-shaped, nonamyloid, smooth to roughened; spore print white.

• Habitat

  Solitary to clustered at the base of conifer stumps, trees, or buried wood; fruiting during the middle of the mushroom season, usually late November through December.

• Edibility

  Inedible; tough and bitter.

• Comments

  Jahnoporus hirtus is a tough, bitter tasting, ground-dwelling polypore recognized by a grey-brown, finely pubescent cap and eccentric stipe usually well-rooted in the substrate. Additionally, it has relatively small, white pores and non-amyloid, spindle-shaped spores. Though not abundant, it is found in our area every year. Bondarzewia montana is similar when fruiting singly, but has larger pores, lacks a distinct stipe (the cap gradually merges into the stipe), is slightly sour, not bitter in taste, and the spores are round, with amyloid ornamentation. Several Albatrellus species also resemble Jahnoporus hirtus, but only A. pescaprae is likely to be confused with it. The latter is distinguished by a brown to mahogany-brown, more conspicuously pubescent cap, larger white to cream colored pores, and the stipe is neither grey/brown or pubescent. Microscopically, it can also be told apart by smooth, elliptical spores that are 4.5-9 x 5-6 µm. Note, our spore measurements for Jahnoporus hirtus are smaller than reported by Gilbertson (12.5-17 x 4.5-5.5 µm) but we have checked only a few collections.

• Other Descriptions and Photos
  • Michael Wood: Jahnoporus hirtus (CP)
  • Michael Wood: Jahnoporus hirtus (CP)
  • Arora (1986): p. 560 (D), p. 561 (p) [Polyporus hirtus]
  • Gilbertson & Ryvarden (1986): p. 408 (D), fig. 196 (I)
  • Lincoff: p. 480 (D), plate 465 (CP) [Polyporus hirtus]

  (D=Description; I=Illustration; P=Photo; CP=Color Photo)