Boletus oliveisporus

Description

Boletus oliveisporus is a southern bolete. It is found under longleaf pine and loblolly pine. The stem is a most distinctive feature: when young the apex is yellow and the base is brown, with a bright pinkish-red zone in between. With maturity the brown shades move upwards, conquering the red zone. It is not reticulate, but on close inspection, the stem surface appears "punctate" with tiny dots.

Yellow to greenish-yellow pores age toward olive-yellow, & quickly bruise blue. Yellow cap flesh blues, but sometimes slowly. Likes oak, pine, and may grow on stumps.

Ceriomyces oliveisporus is a synonym.

Mushroom Identification

1. Ecology

   Mycorrhizal with longleaf pine and loblolly pine; growing alone, scattered, or gregariously; reported by Singer (1947) to sometimes appear on stumps; summer and fall; along the Gulf Coast and the southeastern Atlantic Coast.

2. Cap

   6-18 cm; convex, becoming broadly convex or almost flat; dry; dull; smooth or finely velvety; reddish-brown to brown; bruising blue to black on handling; with a slightly overhanging sterile margin.

3. Pore Surface

   Yellow, becoming olive-yellow; bruising promptly blue, then slowly brown; 1-2 pores per mm at maturity; tubes to 2 cm deep.

4. Stem

   4-8.5 cm long; 1-5 cm thick; more or less equal; solid; yellow at the apex and brown at the base, often with a pinkish-red zone in between; appearing finely punctate; becoming brown overall from the base up; not reticulate.

5. Flesh

   Whitish to yellow; bluing on exposure.

6. Odor and Taste

   Not distinctive.

7. Chemical Reactions

   Ammonia negative to slowly red or blackish on cap surface; erasing blued areas of flesh to yellowish or orangish. KOH orange to negative or brownish on cap surface; yellowish to orangish on flesh. Iron salts gray on cap surface; greenish on flesh.

8. Spore Print

   Olive brown.

9. Microscopic Features

   Spores 11-17 x 4-6 µ; smooth; subfusiform; yellowish in KOH. Hymenial cystidia fusoid to fusoid-ventricose; yellowish in KOH, often with refractive contents; to about 65 x 10 µ. Pileipellis is a cutis of cylindric hyphae 4-8 µ wide.

Photo sources:

Photo 1 - Author: Geoff Balme (geoff balme) (CC BY-SA 3.0)

Photo 2 - Author: I. G. Safonov (IGSafonov) (CC BY-SA 3.0)

Photo 3 - Author: Luke Smithson (Mycofreak ) (CC BY-SA 3.0)