Brown Roll-Rim (Paxillus involutus)

Edibility

Deadly

Lookalike Danger

2 / 5

Habitat

🌳 Birch

Season

Aug – Oct

"Once considered edible. Now known to accumulate over years and trigger autoimmune hemolysis. Lethal."

🌳 Host Trees & Plants

This species is found with or partners with the following hosts. Ectomycorrhizal hosts (green border) form a root-level partnership; ericoid / arbutoid shrubs (purple border) share the same mycorrhizal networks.

Birch

Betula spp.

Ectomycorrhizal

Chaga, birch bolete, birch polypore host.

Habitat

Wide range: under birch, pine, spruce, and oak across the northern hemisphere. Summer through late fall.

Season Windows by Region

Region

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Glacier / Flathead NF

MT · 3,500–8,500 ft

Bitterroot / Sapphire

MT · 3,500–9,000 ft

Helena / Big Belts

MT · 4,000–8,500 ft

Gallatin / Madison

MT · 5,500–10,500 ft

Beartooth / Absaroka

MT · 5,000–12,000 ft

Sawtooth / Stanley Basin

ID · 6,000–10,500 ft

Clearwater Mountains

ID · 2,500–7,500 ft

Boise Mountains

ID · 4,000–9,500 ft

Salmon River / Lemhi

ID · 4,500–10,000 ft

Sun Valley / Wood River

ID · 5,500–10,500 ft

Bighorn Mountains

WY · 5,500–13,000 ft

Bridger-Teton / Tetons

WY · 6,000–13,500 ft

Wind River Range

WY · 7,000–13,800 ft

Absaroka / Shoshone NF

WY · 6,000–12,500 ft

North Cascades

WA · 1,500–8,000 ft

Central Cascades / Snoqualmie

WA · 1,500–7,000 ft

Olympic Peninsula

WA · 500–6,000 ft

Gifford Pinchot / South Cascades

WA · 1,000–8,000 ft

Okanogan Highlands

WA · 2,500–7,500 ft

Mt Hood / North Oregon Cascades

OR · 2,000–8,000 ft

Central Oregon / Deschutes

OR · 3,500–9,000 ft

South Cascades / Klamath

OR · 4,000–9,000 ft

OR · 3,500–9,500 ft

OR · 4,000–8,000 ft

IL · 600–1,200 ft

MI · 580–1,000 ft

MI · 700–1,400 ft

Northern Lower Peninsula

MI · 600–1,700 ft

MI · 600–1,979 ft

WI · 650–1,700 ft

WI · 750–1,400 ft

WI · 1,000–1,950 ft

Eastern IA River Valleys

IA · 550–1,100 ft

SE MN Driftless

MN · 650–1,350 ft

Central MN

MN · 900–1,500 ft

Catskills / Hudson Valley

NY · 400–4,180 ft

Finger Lakes / Central NY

NY · 500–2,000 ft

ME · 0–1,530 ft

ME · 400–4,170 ft

ME · 500–5,267 ft

NH · 800–6,288 ft

Lakes Region / Southern NH

NH · 300–1,800 ft

Green Mountains

VT · 800–4,393 ft

Northeast Kingdom

VT · 600–3,300 ft

Berkshires / Western MA

MA · 500–3,491 ft

Willamette Valley / Columbia Gorge

OR · 200–1,500 ft

Turtle Mountain SF

ND · 1,800–2,400 ft

Pembina Gorge

ND · 850–1,500 ft

Black Hills NF

SD · 3,200–7,242 ft

Custer NF / Slim Buttes

SD · 3,000–4,000 ft

Pine Ridge / Oglala NG

NE · 3,400–5,000 ft

Niobrara River Valley

NE · 1,900–2,700 ft

Superior NF / BWCA

MN · 1,300–2,301 ft

Chippewa NF

MN · 1,200–1,500 ft

NE Iowa Driftless / Effigy Mounds

IA · 650–1,250 ft

Adirondacks

NY · 1,000–5,344 ft

MN North Shore / Sawtooth

MN · 600–2,301 ft

SE South Dakota / Newton Hills

SD · 1,300–1,550 ft

Sheyenne NG Oak Savanna

ND · 1,000–1,350 ft

Minnesota River Valley

MN · 800–1,150 ft

Growing Requirements

Min Soil Temp

55°F

Moisture Need

rain 0.5in 7d

Drought Tolerance

moderate

Elevation Range

0–13,800 ft

Look-Alikes

Lactarius spp. (Milk Caps)

Milk caps exude latex when cut; Paxillus does not. Ensure you bleed-test every brown gilled mushroom before considering it edible.

Chroogomphus / Gomphidius

Edible spike-cap mushrooms with similar color. Different gill structure.

Identification Tips

✓Stop ALL consumption — even decades of safe meals can end in a fatal hemolytic crisis
✓Inrolled cap edge + brown gills that bruise brown = Paxillus
✓Published cases: 72-year-old forager died after 50+ years of eating them

Brown Roll-Rim

🌳 Host Trees & Plants

Habitat

Season Windows by Region

Growing Requirements

Look-Alikes

Lactarius spp. (Milk Caps)

Chroogomphus / Gomphidius

Identification Tips

Field Notes

Found Brown Roll-Rim?