Butyriboletus primiregius (“Red-Capped Butter Bolete”)

Oft-pitted/wrinkled cap is usually bright rose- pink to -red. Yellow, oft-bulbous, finely netted stem stains blue. Grows w/mountain conifers in spring.

Description

by Alan Rockefeller

by Alan Rockefeller

by Alan Rockefeller

by Alan Rockefeller

by Alan Rockefeller

Yes, the pores do bruise blue. By Alan Rockefeller

Name in North American Boletes: Boletus regius

Genus: Butyriboletus

  • Genus 2: Boletus

Species: primiregius

  • Species 2: regius

Common Name: Red-Capped Butter Bolete

Tells: Oft-pitted/wrinkled cap is usually bright rose- pink to -red. Yellow, oft-bulbous, finely netted stem stains blue. Grows w/mountain conifers in spring.

Other Information: Yellow pores age darker & bruise blue. Yellow cap flesh stains slowly & erratically. The cap sometimes has yellow or brown tones, especially near the margin. The stem sometimes has reddish tints, especially by the base.

Science Notes: Genetic tests have moved the mushroom f/k/a “Boletus regius” to a newly erected genus called “Butyriboletus” (“butyri” being latin for “butter” and this being one of the Butter Boletes); reserved the name “regius” for the European species; and divided the North American version into three separate species. This one (grows w/mountain conifers in spring), Butyriboletus querciiregius (grows w/oak in autumn), & Bu. autumniregius (grows w/mid-elevation mixed woods or conifers, NOT oak, in autumn).

Edibility: Good

CHEMICAL TESTS:

  • NH4OH (Ammonia): No data.
  • KOH: No data.
  • FeSO4 (Iron Salts): Cap surface turns pale purplish. Cap flesh turns grayish.

Links:

National Audubon Society Field guide to Mushrooms, Gary Lincoff 0 Mushrooms of West Virginia and the Central Appalachians 0 North American Boletes 147

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