GuideAbout

What’s happening outside now.

Look closerFungi

Artist's conk: the shelf fungus you can draw on

November to March

Artist's conk is a thick, woody bracket fungus that grows on hardwood trunks and stumps and stays there for years. Its white underside bruises brown wherever it is scratched, so a stick or a fingernail leaves a visible line.

Why this time of year

The fungus is there all year, but bare winter woods are when you can actually see it: no leaves, no undergrowth, and a gray-brown shelf on a trunk reads from twenty feet away.

How to notice it

  1. Look for a hard, gray to brown, shelf-like growth jutting out from the trunk or stump of a hardwood, most often maple, beech, oak or birch. A big one is eight to twelve inches across.
  2. Check the top surface for concentric growth zones and furrows. The conk adds growth year after year, but the ridges on top are not a reliable year count: the true annual layers are the spore tubes stacked underneath, which you would only see in a cut section.
  3. Look at the flat underside. It should be white to pale cream and feel smooth, almost chalky.
  4. On a fallen log or a stump, gently scratch a line or a letter into the white underside with a stick. Watch it darken to brown and stay marked.

Try this with kids: Find a hard shelf growing straight out of a log. Scratch a letter into its white underside with a stick and watch the letter turn brown.

bracket fungus: a fungus that grows as a hard, shelf-like structure on a tree or log instead of a mushroom with a cap and stem

Safety

  • Draw on conks on fallen logs, stumps or a tree in your own yard. Marking living things on conservation land, DCR reservations and Trustees properties is generally not allowed, and the mark lasts.
  • Do not eat any wild fungus on the strength of a card. This one is woody and is not food.
  • This fungus rots heartwood and sapwood, and a tree carrying conks can fail without showing any other symptom. Do not climb on, lean against or linger under a trunk that has them.

Sources

  • umass.eduUMass Extension fact sheet, updated April 5 2024. Ganoderma applanatum causes root and trunk rot of living hardwoods, with maple, beech and oak the primary hosts IN SOUTHERN NEW ENGLAND plus birch, ash, sycamore, aspen, willow and basswood; the upper surface is dull and develops concentric rings as it grows annually; conks typically survive five to ten years, in some cases longer, reaching 8-12 inches wide; the fungus decays heartwood and sapwood, the presence of conks often means extensive decay, and infected trees may suffer stem failure or uprooting without showing any prior symptoms
  • mushroomexpert.comThe pore surface is white to grayish and bruises yellow to brownish then dark brown, which is the basis of the artist's fungus name; tubes are in annual layers separated by brown tissue, each layer 0.5-2 cm deep, and individuals develop for many years by producing a new spore-producing tube layer BENEATH the previous year's layer; the flesh is woody rather than flexible; the cap surface is often furrowed in zones

Checked against these sources on September 15, 2026.

In the guide for November, December, January, February, March

Also worth noticing