Guide

Look closerFungi

Split gill fungus, the fan that shrivels and revives

All year

Split gill is a small, fuzzy, grayish-white fan fungus that grows on dead hardwood branches and logs. Its gills are split down the middle, and the fungus can shrivel through dry spells and start working again once rain wets it.

Why this time of year

Split gill is out all year, and because it shrivels and waits for moisture instead of dying back, the little fans are still on logs and woodpiles through the cold months. After a wet spell they open up and go back to shedding spores.

How to notice it

  1. Check fallen hardwood branches, log piles, and stacked firewood for clusters of small fuzzy fans, about 1/4 to 1 1/2 inches across, grayish-white to brownish.
  2. Without picking it, bend down or use your phone camera to look at the underside. Each gill-like ridge is split lengthwise into two halves.
  3. Go back to the same fans on a dry day and again after rain. Dry, they look shriveled and the split halves curl in over the underside. Wet, they are softer and flatter, and the underside is open.
  4. Take a close-up photo each time so you can compare the dry and wet looks side by side.

Try this with kids: Crouch down and look under one little fan without touching it. Can you find a gill that is split in two, like a zipper?

Word to know: “Gills”: the ridged underside of a mushroom where its spores are made.

Safety

  • Not edible. Look and photograph only, and leave it on the wood.

Sources

  • mdc.mo.govMissouri Dept of Conservation: gill-like folds split lengthwise; 'It shrivels up during dry times and revives when wet conditions return'; year-round; on dead deciduous branches; 1/4-1 1/2 inches; not edible.
  • mushroomexpert.comMushroomExpert (Kuo): gills appear split down the middle; year-round, survives by shriveling and waiting for moisture; on hardwood sticks and logs; widely distributed in North America.
  • mykoweb.comVellinga, Mycena News 2013: in drought the lamellae roll up and cover the underside (citing Buller); in wet weather they straighten out, exposing spore surface.
  • mcht.orgMaine Coast Heritage Trust: split gill on logs and woodpiles in mid-coast Maine in January, in spore dispersal position when wet.
  • api.inaturalist.orgiNaturalist research-grade Massachusetts observations by month: Jan 70, Feb 59, Mar 98, Apr 118, May 60, Jun 59, Jul 67, Aug 46, Sep 40, Oct 75, Nov 77, Dec 81.

Checked against these sources on November 3, 2026.

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