Guide

Look closerFungi

Tinder conk: the gray hoof fungus on birch and beech

All year

Tinder conk is a hard, gray, hoof-shaped fungus that grows on the trunks of living and standing dead birch and beech. It lives for years and adds a new layer of growth each year, so you can find it in any month, and it can be easier to spot on bare trunks after the leaves fall.

Why this time of year

The conk lasts for years, so it is there in every season, and the gray hoofs can stand out more on birch and beech trunks once the leaves are down.

How to notice it

  1. From the trail, scan birch and beech trunks for a gray lump shaped like a horse's hoof, sticking straight out from the bark.
  2. Look at it from the side. The top has curved gray bands, one ridge stacked on another.
  3. Look at its surface. Tinder conk is hard and woody, not soft or spongy, and its crust is smooth rather than cracked.
  4. Leave it on the tree. A conk on a trunk means the wood inside is rotting, so admire it from the ground and do not push or climb on the tree.

Try this with kids: Count the gray bands on the hoof, starting from the top. How many can you find without touching the tree?

Word to know: “Conk”: the hard, shelf-like fruiting body of a fungus that rots wood.

Safety

  • A conk on a trunk means the wood inside is well rotted, and a dead birch or beech can drop branches or snap. Look from a few steps away, do not push, shake or climb the tree, and stay out from under dead trunks on windy days.
  • Not for eating. Leave the conk on the tree.

Sources

  • tidcf.nrcan.gc.caNatural Resources Canada: most encountered on birch and beech; on trunks of living and standing dead hardwoods; mature conks hoof-shaped with smooth non-cracked hard crust, concentrically furrowed in shades of gray; perennial, woody, annual pore layers for 30 years or more; occurs in the northern half of the US; inner tissue used for starting fires; indicates advanced decay.
  • botit.botany.wisc.eduTom Volk (UW-La Crosse): usually hoof-shaped and perennial, almost always on birch; fruiting bodies present year-round; used as tinder for starting fires.
  • ncslg.cals.ncsu.eduNC State: range North Carolina north to SE Canada; hard crust, woody; common on birch and beech.
  • apps.extension.umn.eduUMN Extension: Fomes fomentarius is a heart rot of birch; trunk center becomes soft and crumbling.

Checked against these sources on October 16, 2026.

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