Veiled Polypore Cryptoporus volvatus — the sealed polypore of burned conifer forests
Cryptoporus volvatus is one of the most recognizable polypores in the Pacific Northwest. Round to hoof-shaped, smooth and shiny, with a sealed underside that hides its pore surface — no other bracket fungus looks quite like it. You’ll find it studding the bark of recently dead conifers, especially pines and firs, sometimes dozens of fruitbodies marching up a single trunk.
It is especially common after forest fires, fruiting in quantity on fire-killed trees, and it has an unusual partnership with the insects that bore into dying conifers.
Scout Post-Fire Habitat on Forayz
Use burn perimeter overlays and satellite basemaps to find recently burned conifer stands — prime territory for veiled polypores and post-fire species.
Identification
| Feature | Description |
|---|---|
| Fruitbody | Small: 1–6 cm across, occasionally 8. Rounded to hoof-shaped, with a dry, glossy top that may show a fine net-like pattern or break up into thin flakes. |
| Color | Fresh ones are butterscotch, tan, or reddish brown; older and dried ones fade to pale tan or almost white. |
| Veil | A thick, rubbery skin closes off the whole underside, forming a hollow pocket over the pores. Older ones usually have one or more small holes in it, round or ragged. |
| Pores | Very small and close-packed, hidden inside the pocket. White to pale buff at first, turning pinkish or brownish with age. |
| Flesh | Rubbery when fresh, drying tough and corky; whitish to cream. |
| Stipe | Absent — attaches directly to bark. |
| Odor | Not distinctive; sometimes rubbery or faintly fragrant. |
| Taste | A little bitter. |
| Spores | A normal spore print is hard to get, since the spores collect inside the pocket; the spore mass is pinkish (Arora) to cream (Miller). |
The sealed pore surface is the giveaway
No other PNW polypore closes its pore surface inside a thick rubbery skin. A small, smooth, rounded bracket on conifer bark whose underside is a sealed pocket rather than open pores is Cryptoporus volvatus. The small holes that appear in the pocket as it matures are another good field mark.
Ecology & Insect Partnership
The sealed pore surface is part of how the fungus spreads. Its spores travel on the wind like other polypores’, but insects also carry them from tree to tree (MycoMatch).
Over several months many kinds of insect — as many as 17 in one study — feed on the fruitbody and pick up spores inside the pocket. When they leave to bore into another tree and lay eggs, they carry the spores with them, and the next year new fruitbodies grow out of those bore holes (Siegel & Schwarz, Mushrooms of Cascadia). The approach works: the veiled polypore is found across much of North America.
Habitat & Where to Look
Look for the veiled polypore on recently killed conifers, especially pines, true firs, and Douglas-fir, and occasionally on old living trees (Arora). Fruitbodies sit in the bark furrows up and down the trunk, sometimes scattered, sometimes dozens together. It typically appears about a year after a tree is killed by fire or bark beetles and rots the outer wood before other decay fungi take over (Gilbertson).
In the PNW: Common on both sides of the Cascades and on the drier, eastern side of the Olympic Peninsula. Occasional in the inland valleys, and rare on the coast and in the Coast Range.
After fires: It is especially plentiful in the mountains after forest fires. In a recent burn, expect to see it, sometimes in large numbers on standing snags.
Find Recent Burns in the Cascades
Forayz maps burn perimeters from recent and past fire seasons across the western US. Switch to satellite imagery to spot standing dead conifers in burned areas.
Season & Timing
Fruitbodies are annual, with new flushes in spring and again in late summer before the fall rains (Siegel & Schwarz). But they are tough and corky and last for months, some into the next year, so you can find the veiled polypore on dead conifers at almost any time. When it is reported mostly reflects when people are out looking, not when it fruits.
Edibility
Inedible: the flesh is rubbery to corky and tastes bitter.
Similar Species
The sealed pore surface sets the veiled polypore apart. A few other polypores share its dead conifers but are easy to tell apart:
- Red belt conk (Fomitopsis mounceae, formerly called F. pinicola): Much larger and perennial, with an open, creamy pore surface and usually a reddish band on the cap. See the polypores page.
- Trichaptum abietinum: Thin, overlapping shelves with violet pores that turn ragged with age; grows only on conifers.
- Trametes species: Thin brackets with clearly visible pores. Usually on hardwoods rather than conifers.
Sources: Mushrooms of Cascadia (Siegel & Schwarz, 2024); MycoMatch (© Ian Gibson), a compilation of published descriptions through which most other field-guide authors named here are quoted.