MushieMushroom undersides explained: true gills, false ridges, pores and spines
Looking underneath the cap is one of the fastest ways to narrow a mushroom to a group. Mushrooms release spores from four main underside structures: sharp blade-like true gills (agarics and Amanitas), blunt forked ridges or smooth surfaces (chanterelles and trumpets), sponge-like tubes and pores (boletes and polypores), or hanging icicle-like spines (tooth fungi such as lion's mane).
Key field checks for gills vs pores vs ridges
| Feature / Clue | What it means in the field |
|---|---|
| True gills (blades) | Thin, knife-edged plates radiating under the cap. Check whether they are free from the stem (Amanita, Agaricus) or run down the stem (oyster mushroom, jack-o'-lantern, fool's funnel). |
| False gills (blunt ridges) | Low, rounded, forked veins that look melted onto the cap and stem—the hallmark of true chanterelles. |
| Sponge pores (tubes) | A cushion of tiny round or angular holes underneath the cap, seen on porcini, bitter bolete and chicken of the woods. |
| Teeth or spines | Soft dangling icicles instead of gills or pores, characteristic of lion's mane and hedgehog mushrooms. |
Deadly species in this group (1)
Poisonous species in this group (1)
Inedible species in this group (1)
Edible with caution species in this group (1)
Edible (expert ID) species in this group (6)
Frequently asked questions
How do you tell true gills from false gills on a mushroom?
True gills are thin, flexible blades with knife-like edges that can be flicked back and forth like book pages. False gills (as on a chanterelle) are thick, blunt, forked folds of the cap flesh itself.
What does it mean if a mushroom has a sponge underneath instead of gills?
A spongy layer of tubes and pores underneath a fleshy cap and central stem usually places the mushroom in the bolete group (such as porcini or bitter bolete).
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