Boletus billieae (“Billie’s Bolete”)

Mottled cap bruises bluish & tastes bad. Yellow flesh stains blue, often w/red in the stem base. Yellow stem bruises blue, fading to brown. Yellow netting darkens lower down or if handled.

SKU: Boletus speciosus var. brunneus-1-1 Categories: , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,


Name in North American Boletes: N/A

Genus: Boletus

  • Genus 2: Butyriboletus. Multigene DNA testing in 2019 suggests that the species probably belongs in Butyriboletus but those are raw results that have not been formally published.

Species: billieae

Common Name: “Billie’s Bolete” (after the wife of Dr. Ernst E. Both)

Tells: Found only in Cape Cod. Chocolate- to purplish-brown cap. Red stem (especially low) with yellow reticulation. Pale yellow flesh stains slowly blue.

Other Information: Odor described as “reminiscent of chocolate chip cookies when dried!” Cap bruises reddish. Yellow pores age greenish on their way toward olive, and quickly bruise blue. Stem is deep red at the bottom, but may get yellower going up. Likes sandy soil. White mycelium.

Science Notes:

Edibility: Unknown.


  • NH4OH (Ammonia): Cap surface turns amber.
  • KOH: Cap surface turns dark amber before fading to red brown.
  • FeSO4 (Iron Salts): Cap surface turns grayish green.


National Audubon Society Field guide to Mushrooms, Gary Lincoff 0 Mushrooms of West Virginia and the Central Appalachians 0 North American Boletes 0 95

Got something to discuss?

Justin Douglas
2 years 8 months ago

This mushroom is not secluded to cape cod as I found this species growing in central NH. This is an ID I am very confident in.

2 years 7 months ago

We found this mushroom recently in coastal Maine.

Scott Pavelle
2 years 7 months ago

Approving because the location makes sense. But was there an ID from a nationally recognized authority? That is the standard for changing any of our filters.