Boletellus chrysenteroides

🏷️ Description

Boletellus chrysenteroides is a fascinating and somewhat rare mushroom from the family Boletaceae, known for its patchwork of features borrowed from other bolete relatives. With its dark cracking cap, yellowish pores, blue-staining flesh, and scabrous stem, this mushroom is a summer-to-fall treat for foragers and fungi fans in eastern North America! 🌳🍂

📖 Taxonomy & Naming

First described by mycologist Wally Snell in 1936 as Boletus chrysenteroides, this species was later transferred to the genus Boletellus in 1941. Its specific name reflects its resemblance to Xerocomellus chrysenteron, another cracking-capped bolete.

🔎 Identification

This mushroom can feel like a confusing mix of bolete traits — but knowing what to look for makes it much easier to spot!

🧢 Cap

• Size: (2 to 10 cm) 0.79 to 3.94 inches wide

• Shape: Convex to broadly convex, flattening with age

• Texture: Dry, initially finely velvety, becoming nearly bald

• Color: Dark brown to nearly black when young, aging to medium to pale brown

• Feature: Often cracks with age, revealing red flesh in the splits

🌼 Pore Surface

• Color: Bright yellow to dull yellow, becoming olive yellow

• Bruising: Slowly stains blue, then may turn brown

• Pores: 1–2 per mm, round to angular

• Tubes: Up to (1 cm) 0.39 inches deep

📏 Stem

• Size: (2 to 13 cm) 0.79 to 5.12 inches long, up to (1.5 cm) 0.59 inches thick

• Shape: More or less equal width throughout

• Surface: Initially covered with Leccinum-like brownish scabers, later forming hairy or scaly clusters that can resemble reticulation

• Color: Yellowish to brownish when young, becoming reddish to purplish red mid-stem with age

• Staining: Bluish when handled, later sometimes turning reddish

🥩 Flesh

• Color: Pale yellow to whitish, may develop reddish tones in older specimens or around damaged areas

• Staining: Turns blue when cut or bruised

👃 Odor and Taste

• Not distinctive

🧪 Chemical Reactions

• Ammonia: Black on cap, brownish on flesh

• KOH (Potassium Hydroxide): Black on cap, brownish on flesh

• Iron Salts: Olive on flesh

🥄 Spore Print

• Olive brown

🔬 Microscopic Features

• Spores: 10–17 × 5–8 µm, ellipsoid, with longitudinally twisted grooves

• In KOH: Spores appear yellow

• Pileipellis: A trichoderm, with terminal elements often cystidioid

🌳 Habitat & Distribution

Boletellus chrysenteroides can be found in eastern North America, from June to September. It’s especially fond of:

• Well-decayed oak and hemlock wood 🌳

• Old oak stumps and logs

• Often appearing alone, sometimes seeming to fruit directly from wood — a rather unusual trait for a bolete!

This species is typically associated with oak but can also be found near pine and eastern hemlock. Presumed to be mycorrhizal, though it regularly appears in unexpected spots like rotting wood.

🍴 Edibility

Considered good by those familiar with it — though like any bolete, caution and accurate identification are essential before consuming wild mushrooms.

Photo sources:

Photo 1, 2 - Author: aarongunnar (CC BY 4.0)

Photo 3 - Author: Dave Muska (CC BY 4.0)

Photo 4 - Author: Zihao Wang (CC BY 4.0)