In the middle of September I received good news in an e-mail from the Norfolk Fungus Study Group’s DNA Team:
“Your specimen submitted as Steccherinum oreophilum has been identified by DNA as Irpex oreophilus, which is a synonym, so we had the correct identification!
This species will be entered onto the Norfolk Mycota and the sequence added to Genbank. But it can’t yet be placed on FRDBI as it is not on the UKSI…“ (note 1).
I had collected and dried a sample of a fungus and passed it to the DNA Team because it was the first time the species had been found in Norfolk. I couldn’t find any previous records of the fungus in the British isles and this, combined with the species’ absence from the FRDBI and UKSI, makes me think it could be a new species for the British Isles.

Steccherinum oreophilum (Irpex oreophilus) growing on the cut end of a willow stump. 1st March 2025.
Finding Steccherinum oreophilum
At the beginning of March 2025 my wife Vanna and I were walking along a path by the River Wensum in west Norwich, looking for Scarlet Elfcups and Alder Goblets, which we usually find there in late winter. We found both of them.
Vanna then spotted some unusual white fungi growing on the end of a cut willow stump on the edge of a dyke. The stump was still alive and had re-sprouted but the very end was dead and this is where the fungi were growing.
We took a closer look. The fungi were small (7 x 10mm across and about 4mm thick) and slender but tough white brackets with a tinge of pale orange. The top surface was felty but the undersides with their white to pale buff teeth (up to 3mm long) really caught our attention. The fungi had no obvious smell.
We took a sample home for a closer look.
I checked my books and posted photographs on Facebook. The fungus resembled the photograph of Steccherinum oreophilum in Volume 2 of Laessoe and Petersen’s two volume “Fungi of Temperate Europe” (page 1048) and James Emerson (who has an excellent knowledge of wildlife and a very good eye for fungi) thought this too. I looked on the internet, where the information was from the United States, Finland and the Czech Republic (note 2).
Steccherinum oreophilum in greater detail
I did some microscopy, looking at the spores and cystidia.
The spores measured 4.5 – 5 x 3 micrometres and were white and non-amyloid. (The photo above is at x1000 magnification. The spores have been stained with Melzer’s reagent and haven’t turned dark brown.)
The cystidia (projections from the edge of the fruitbody) were covered in crystals. (The photo above is at x1000 magnification. The tissue has been stained in Congo red.)
Laessoe and Petersen also mention a close relative of Steccherinum oreophilum called Irpex lacteus. Like Steccherinum oreophilum, it forms small white annual brackets which can have teeth on the underside. Steccherinum oreophilum has smaller fruitbodies and the crucial microscopic difference is that Steccherinum oreophilum has clamps, which Irpex lacteus lacks. So the final stage was to search for clamps.
A clamp connection is a hook-like structure formed by growing hyphal cells of Basidiomycete fungi. Some species have them, others don’t. They can be hard to find and an absence of clamps is hard to prove (note 3).
My friend Anne and I took a look and found some clamps straightaway. (I was glad to have a second opinion from a more experienced mycologist.)
So it looked like we’d found Steccherinum oreophilum. I dried my sample at 60 degrees Celsius for eight hours in a food dehydrator, froze it (to kill anything living in it) and then defrosted it at room temperature. I passed my sample with paperwork and photos to the DNA Team and It matches with other DNA samples of Steccherinum oreophilum / Irpex oreophilus (note 4).
New for Norfolk? – Yes. New for the British Isles? – Possibly.
Is it new for the British Isles? Possibly, but someone else’s record may not have made it to the databases yet, so we’ll see.
Regardless, Vanna found a lovely little fungus and I’m glad I bothered to look at it.
Notes
Note 1 – The Fungal Records Database of Britain & Ireland (FRDBI) is a database of fungal records maintained by the British Mycological Society. Local fungus study groups send in fungi records for inclusion on this database, which can be searched for useful information such as dates of records, locations where a species has been found found and associations with other organisms (e.g. what type of wood a fungus was growing on or its association with particular trees).
The United Kingdom Species Inventory (UKSI) is a database of UK wildlife taxonomy and nomenclature. It is maintained by the Natural History Museum in London and forms the foundation for the largest biological recording and reporting systems in the UK.
iNaturalist UK has a page for Steccherinum oreophilum with several pictures (taken in the United States and in Russia). At the time of writing, none of the observations is from the British Isles.
Note 2 – Steccherinum oreophilum occurs in North America and in other parts of Europe. It is featured on the Texas Mushrooms website and on the Mykoweb website (Czech Republic) and the Finnish Biodiversity Information Service website.
Note 3 – In his excellent book “Fascinated By Fungi“, Pat O’Reilly says:
“… proving a negative can take forever. When your key or field guide says ‘clamps absent’ how long should you search before concluding that your specimen has no clamps? There is no right answer, but after searching for a few minutes you, like me, may begin to care a lot less about clamps and decide to move on and look for something else.”
Pat O’Reilly, “Fascinated By Fungi” (Second edition 2022, Coch-y-Bonddu Books Ltd, Machynlleth.)
Note 4 – See “From molecules to mushrooms: DNA sequencing in Norfolk” for an introduction to the Norfolk Fungus Study Group’s DNA Team.