Retiboletus ornatipes

🏷️ Description

Retiboletus ornatipes, commonly known as the ornate-stalked bolete or goldstalk, is a striking bolete mushroom native to eastern North America, especially under oak and beech trees. Originally described as Boletus ornatipes by Charles Peck in 1878, it was moved to the genus Retiboletus in 2002 based on DNA studies.

This species is notable for its bright yellow, netted stem, yellow flesh, and a cap that varies in color—from gray and brown to sulfur yellow and olive. It’s often found growing alone or in small groups during summer and fall, particularly in mossy or disturbed areas of hardwood forests.

📌 Tips for Mushroom Hunters

• Look for yellow pores and heavily reticulated yellow stem

• Cap often has darker center and yellow edge

• Check for lack of blue staining, a distinctive feature

• Use chemical reagents (KOH, NH₄OH, FeSO₄) for advanced ID

• Handle with care—it may stain your hands yellow!

• Appears bug-resistant, a rare plus!

🧠 Taxonomy & Classification

• Family: Boletaceae

• Genus: Retiboletus

• Synonym: Boletus ornatipes

• DNA Insight: Molecular research confirms Retiboletus ornatipes as genetically distinct from closely related species like R. griseus or B. retipes.

🔎 Identification

🟡 Cap

• Size: 1.5 to 8 inches (4 to 20 cm)

• Shape: Convex to broadly convex, often becoming flatter with age

• Texture: Velvety when young, later bald

• Color: Sulfur yellow, gray, medium brown, olive/brown, or mottled; usually darker at the center and yellow toward the margin

• Margin: Slightly inrolled when young

🌕 Pores (Underside)

• Color: Bright yellow turning orangish-yellow to olive-yellow with age

• Bruising: Slowly orangish-brown or not at all

• Pore Density: 2–3 per mm

• Tube Depth: Up to 0.59 inches (15 mm)

📏 Stem

• Size: 2.4 to 4.7 inches (6 to 12 cm) tall, 0.4 to 1.2 inches (1 to 3 cm) thick

• Shape: Equal or tapered toward the base

• Reticulation: Highly netted, coarse and wide-meshed from top to bottom

• Color: Bright golden-yellow, browns with age or handling

• Base: Yellow mycelium

• Finger stain: Yellow when handled

🟡 Flesh

• Color: Yellow to golden yellow

• Staining: No color change when sliced

• Texture: Firm

• Taste: Mild to somewhat bitter

• Odor: Not distinctive

🌱 Ecology & Habitat

• Type: Mycorrhizal

• Hosts: Primarily oaks and beech, but also found under other hardwoods

• Location: Eastern North America, from Québec to Kentucky, and south to North Carolina and Costa Rica (related variants)

• Season: July to September (summer and fall)

• Habitat: Mossy ground, hardwood forests, sometimes disturbed areas

🧪 Chemical Reactions

• KOH: Cap: Dark red to reddish-brown. Flesh: Gray

• NH₄OH: Cap/Flesh: Pale brown

• FeSO₄: Cap/Flesh: Negative (no reaction)

• Ammonia: Cap: Orangish to no reaction. Flesh: Negative to greenish

🔬 Microscopic Features

• Spores: 10–12 × 3–4.5 µm, subfusoid, smooth, yellowish in KOH

• Spore Print: Orangish-yellow with slight olive tint

• Cystidia: 35–50 × 5–7.5 µm, fusiform, golden to brownish in KOH

• Pileipellis: Collapsing trichoderm; cells 2.5–10 µm wide, golden-brown in KOH

🍽️ Edibility & Culinary Notes

Edibility: Iffy. While some guides list it as inedible, others call it choice if not bitter.

Flavor: Can range from mild to bitter. When not bitter, the flavor is reminiscent of a milder porcini.

Preparation Tip: Best cooked—dehydrated specimens rehydrate well and hold texture. A user-prepared sample sautéed in marsala wine had mild flavor with some initial bitterness that diminished during eating.

Recommendation: Try small amounts only with expert identification.

👀 Look-Alikes

• Retiboletus griseus – White flesh, non-yellow cap, no red KOH reaction

• Boletus auriflammeus – Brilliant golden cap, pink-tinged flesh

• Retiboletus flavoniger – Related, with deeper brown tones

📜 Synonyms

• Boletus retipes Peck (1872) [1869], Annual report of the state Cabinet of natural history, 23, p. 132

• Boletus ornatipes Peck (1878) [1876], Annual report of the New York state Museum of natural history, 29, p. 67

• Suillus ornatipes (Peck) Kuntze (1898), Revisio generum plantarum, 3, p. 536

Photo sources:

Photo 1 - Author: Annie Weissma (Public Domain)

Photo 2 - Author: Hill Craddock (CC BY 4.0)

Photo 3 - Author: Shelby Lyn Sanders (CC BY 4.0)

Photo 4 - Author: Annie Weissman (Public Domain)