Back in April I found a rather special fungus, Coprinopsis alnivora, on a Norfolk and Norwich Naturalists’ Society field meeting to Sennowe Park, near Guist in central Norfolk.

Rothole Inkcap, Coprinopsis alnivora, Sennowe Park, Norfolk. 6th April 2024.

Sennowe Park is a private property owned by the Cook family, descendants of the Thomas Cook who founded the famous travel firm. It is used for weddings and other events and the current owners kindly allowed us to look around. We were given a tour of the grounds in the morning, mainly looking at trees, then left to wander around in the afternoon.

Rothole Inkcap

On the tour, we walked past an Oak tree growing out in the open and I noticed a handsome fungus growing singly from a wound about five feet up the trunk. It looked rather interesting, not least because of its unusual location, high above the ground. It was an inkcap of some kind, but not one I’d seen before.

I was a bit torn – there was only one fruitbody and it looked rather lovely. But it was also worthy of a closer look and proper identification, so I carefully removed it, placed it in a plastic pot I was carrying and took it home.

Coprinopsis alnivora

Coprinopsis alnivora

When I arrived home I had a look in several fungi books (note 1). In Funga Nordica and Kibby Vol. 3  the nearest candidate seemed to be Coprinopsis mitraespora and Coprinopsis spelaiophila (not previously recorded in Norfolk).

Coprinopsis alnivora

Online, I found details of Coprinopsis alnivora, an even rarer fungus, which was found for the first time in the British Isles on a Beech tree in the New Forest in October 2022.

Russell Wynn and Marcus Ward wrote a detailed blog post about their find in December 2022. The post features some very good photographs and full descriptions of the fungus, including spores (note 2). 

Coprinopsis alnivora is also featured on the Czech Mykologie.net website and later I found it illustrated at the end of Kibby Vol. 4 (note 1).

I wanted to make sure of my identification so I posted photos on the British Mycological Society Facebook page. Iona Fraser and Michel Beeckman immediately confirmed that my find was indeed Coprinopsis alnivora and Russell Wynn added a link to his blog post.

My find was new for Norfolk.

More Details

I wrote up a description of my find:

Cap diameter 27mm. Whitish basal colour, partly covered with dark brown woolly scales. These were easily dislodged, revealing a striated grey upper surface to the cap flesh.

Stem 45 x 6mm, hollow, round in profile, smooth towards the apex and more granular towards the base.

Gills free, crowded. Greyish but turning blackish, with black spores visible on stem beneath. Found late morning and it started to deliquesce by late afternoon. Cap fully deliquesced in two to three days.

Smell not distinctive, slightly “mushroomy”.

Woolly cap tissue.

Spores very dark brown 7.5 – 9  x 6 -7 um, ellipsoid – rhombic, with a central germ pore.

I photographed the spores:

My photo of spores of Coprinopsis alnivora. Magnification x1000, slide mounted in water.

DNA Analysis

Russell Wynn and Marcus Ward dried their specimen and a DNA analysis was carried out.

I decided it would be a good idea to do the same.

Luckily Norfolk Fungus Study Group has a dedicated DNA Team who meet regularly during the year to perform the necessary lab work and analyse results.

My biggest challenge was ensuring the fruitbody I’d collected was in a fit state to analyse.

Russell Wynn and Marcus Ward dried their sample in a food dehydrator for 48 hours at 38 degrees Celsius but at the time I didn’t have a food dehydrator so placed my sample in a plastic dish just above a radiator. (Luckily the central heating was still on at that time of year.)

It was a race to dry the fungus before it turned to ink (deliquesced). By the time it was dry I had a tiny remnant of cap, the stipe and some clotted black “ink” full of spores, which I scraped into a clean plastic tube. I froze the sample and later passed it on to the DNA Team.

Last week I was told the good news that the DNA Team had managed to obtain a useable DNA sequence from my specimen and it was indeed Coprinopsis alnivora.

Coprinopsis alnivora outside the British Isles

Coprinopsis alnivora was first described in the United States, where the type specimen was collected from Washington State.

Subsequently, the fungus was found in Europe and eleven additional samples were collected from five new host trees at nine localities in Europe (Austria, Croatia, and Slovakia). It has a preference for growth in cavities or wounds of living deciduous trees.

The paper “Coprinopsis alnivora (Psathyrellaceae), a rare species from North America is discovered in Europe” describes the discovery of the fungus in Europe (note 3).

It will be interesting to see whether further specimens of Coprinopsis alnivora turn up.

Rothole Inkcap

At the time of writing the name “Rothole Inkcap” is a provisional one. The British Mycological Society are currently consulting on some new English names for fungi and Coprinopsis alnivora is one of them.

Thanks to my friend James Mendelssohn for taking me out to Sennowe Park.

Notes

 Note 1 – The books mentioned are:

“Funga Nordica: Agaricoid, Boletoid, Clavarioid, Cyphelloid and Gastroid Genera” (2012), edited by Henning Knudsen and Jan Vesterholt (Nordsvamp, Copenhagen). A fantastically detailed book with keys and line drawings of spores, cystidia etc.

“Mushrooms and Toadstools of Britain & Europe – Volume 4” (2023), by Geoffrey Kibby. Part of a four volume set of books, beautifully illustrated by the author. Most Coprinopsis species are in Volume 3 (2021) but Coprinopsis alnivora appears at the end of Volume 4 as a recent addition to the British list (pages 106 – 107).

“Funga Nordica” is sadly out of print and secondhand copies are almost impossible to find but all volumes of “Mushrooms and Toadstools of Britain & Europe”are available to buy online.

Note 2 – “Wild New Forest find a potential first for Britain: the inkcap fungus Coprinopsis alnivora” (8th December 2022).

Note 3 – Bednar, R. et al (2022), Phytotaxa Vol 542 (2): pp136-152.