Boletus citriniporus Halling
Mycologia 69: 206. 1977.

Common Name: none

• Pileus

  Cap 4-8 cm broad, convex, broadly so in age; margin at first incurved, then decurved; surface matted tomentose to appressed squamulose, sometimes faintly cracked in older specimens; color dark-brown; context white, firm, moderately thick, unchanging when injured; odor and taste mild.

• Hymenophore

  Tubes 0.5-1.0 cm long, adnate, bright yellow; pores 1-2/mm, unchanging when bruised, colored like the tubes.

• Stipe

  Stipe 4-7 cm long, 1-3 cm thick, solid, equal, subventricose, to slightly clavate, narrowed at the base; surface often yellowish at the apex and sometimes faintly reticulate, elsewhere subglabrous, pallid to pale dingy buff.

• Spores

  Spores--Halling: "(10.5) 12-13.5 x 3.75-4.5 µm, subfusiform and inequilateral in profile, often with a conspicuous suprahilar depression, elliptical to fusiform elliptical in face view".

• Habitat

  Solitary to grouped under oaks (Quercus); in our area under coast live oak (Quercus agrifolia); fruiting from after the fall rains to mid-winter.

• Edibility

  Unknown.

• Comments

  This handsome, uncommon bolete is characterized by a dry, dark-brown cap and bright yellow pores. Its relatively small size and oak habit are also important identifying characters. According to Halling, Boletus citriniporus closest relative in California is B. flaviporus. The latter also has bright yellow pores, but can be distinguished by a viscid, reddish-brown to cinnamon-brown cap.

• References

  Bessette, A.E., Roody, W.C. & Bessette, A.R. (2000). North American Boletes: A Color Guide to the Fleshy Pored Mushrooms. Syracuse University Press: Syracuse, NY. 400 p.
  Halling, R.E. (1977). California Boletes VI. Some unreported species from the Sierra Nevada of California. Mycologia 69: 206-210.

• Other Descriptions and Photos
  • Beverly Hackett: Boletus citriniporus (I)
  • Mushroom Observer: Boletus citriniporus (CP)
  • Bessette et al. (2000): p. 105 (D), p. 289 (CP)
  
  

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