Russell Wynn and Marcus Ward
Summary: On 28 Sept 2022, a potentially new fungi species for Britain was discovered by Russell Wynn and Marcus Ward of Wild New Forest while leading a guided Fungi Explorer walk in the New Forest National Park. A combination of prompt feedback on social media, field observations, and subsequent DNA analysis, enabled the identification to be confirmed as Coprinopsis alnivora, a globally rare inkcap species that has only recently been recorded as new to Europe. This illustrated blog outlines the circumstances of this discovery and documents some of the key identification features.
Over the last three autumns, Wild New Forest have been running a popular series of guided Fungi Explorer walks in various locations in the New Forest, under Forestry England permit. The aim of these walks is to show our guests a wide variety of fungi species and discuss their habitat requirements and role in the wider ecosystem, and to provide opportunities for fungi photography; we also promote the New Forest Code and the Forestry England “look but please don’t pick” guidance.
On 28 Sept we were leading a Fungi Explorer walk when we encountered a clump of large whitish inkcaps emerging from a rotten cavity in a Beech tree about a metre or so off the ground. The habitat was wrong for any of the commoner large inkcaps, so we were immediately alerted to the possibility of something rarer. Russ secured a series of images, and that evening checked them against reference books and online sources; they didn’t seem to fit with anything obvious, so he posted one of the images on the British Mycological Society Facebook page that evening with a tentative identification as one of the rarer Coprinopsis inkcap species.
Three images showing sporocarps of Coprinopsis alnivora, photographed in the New Forest on 29 Sept 2022.
The rapid response highlights the positive power of social media, as within a couple of hours experts from The Netherlands (Michel Beeckman) and Slovakia (Ján Cervenka) excitedly suggested it may be Coprinopsis alnivora, a species only recently described as new to Europe in a paper published in spring 2022 (see images from Fig. 2 of the paper below). Their recommendation was to collect samples for further analysis as soon as possible. And so began a fast-track into the world of fungi sampling, preservation, and analysis!
Images of Coprinopsis alnivora taken in eastern Europe (Fig. 2 in Bednar et al., 2022), showing the morphological similarity to the New Forest specimens.
The first task was to secure permission from the land manager, Forestry England, to collect a couple of samples for detailed study, as the site was on the Crown lands. Permission was promptly granted and by lunchtime on 29 Sept Russ had carefully secured two good specimens and a detailed description (see appended notes).
Two specimens of Coprinopsis alnivora, sampled on 29 Sept 2022 with permission of Forestry England.
The next task was to purchase a food dehydrator and get the specimens dried out as quickly as possible. Again, the online advice provided by Michel and others was invaluable in ensuring this was done correctly (48 hours at 38oC). Once this was completed, a set of samples were passed to Eric Janke at Hampshire Fungi Recording Group (HFRG), and one set were posted to a colleague in Brighton for onward posting to mycologists exploring possible records of Coprinopsis alnivora in Sweden.
The two sampled specimens of Coprinopsis alnivora, being dried on a food dehydrator on 30 Sept 2022.
Eric was able to successfully extract DNA from his specimen, and the samples were sent off to Aberystwyth University for sequencing. The results came back on 07 Nov and encouragingly the New Forest samples were an excellent match for those labelled in genetic databases as Coprinopsis alnivora.
This appears to be the first record for Britain of this species, and Eric will kindly be submitting it via the official channels in his role as HFRG Recorder. The recent European records have come from much further east (Austria, Croatia, and Slovakia), prior to which the species was only known from the original type collection in Washington State in North America, so the New Forest specimen could conceivably have arrived from either direction, or may have just remained well hidden!
Interestingly, additional clusters of what appear to be the same species were observed in an inaccessible cavity several metres up a Beech tree just a short distance from the sampled specimens, and Dave Shute of HFRG found a further cluster a few hundred metres away on 09 Nov. It’s notable that the sampled cluster appeared to be continuously fruiting over a period of at least six weeks, which in our experience is unusual for an inkcap species.
Two images of presumed Coprinopsis alnivora, taken by Dave Shute of HFRG on 09 Nov 2022, close to the site where the specimens shown above were located.
We’ve both been keen wildlife recorders for over two decades, with a particular focus on birds and moths, but despite finding a good selection of extremely rare migrant species we have yet to find a first for Britain. In recent years, we have diversified our interests and identification skills to include other species groups, including fungi, but we never envisaged this would result in a national first! It’s not uncommon for experienced mycologists to find new species of fungi for Britain, particularly in a hotspot like the New Forest where nearly 3000 species are present. However, many of these new discoveries are rather small and/or obscure species that require detailed microscopic examination, so we are fortunate to have found a relatively large and ‘charismatic’ species that can be identified in the field with a reasonably high degree of confidence.
The New Forest is recognised as being internationally important for several groups of fungi, including wood-rotting species associated with dead and decaying Beech trees. It will be interesting to see if Coprinopsis alnivora is found at other New Forest (and UK) locations in the coming years, and whether it is restricted to ancient Beech woodland in our region or is found on other tree species, as it is in eastern Europe.
Finally, we are extremely grateful to everyone involved in various stages of the identification process, particularly Iona Fraser, Michel Beeckman, and Ján Cervenka for their online assistance, Eric Janke (HFRG) for DNA analysis and general support, and Leanne Sergeant (Forestry England) for providing permission to sample.
Coprinopsis alnivora - initial description
Ecology: Saprobic, tufted, rooted in well-decayed wood in rot holes and exposed scars in standing mature Beech trees.
Cap: For the largest specimen, cap was 40mm deep x 50mm wide. Initially spherical then oval when young, expanding and flattening to bell-shaped with a splitting upturned margin. Whitish basal colour when young, but mostly covered with dark brown scales initially, these becoming increasingly confined to upper part of cap during maturation, where restricted to apex of fibrous ‘peaks’ resembling a geodesic dome or moonscape. Scales woolly and easily dislodged on mature specimens, revealing striated grey upper surface to cap flesh.
Gills: free, crowded, and greyish then blackish, although retaining a paler grey halo up to 10mm deep towards apex around stem. Black spores visible on adjacent stems and caps. Quickly deliquescing.
Stem: Hollow and round, stipe length up to 100mm on largest specimen, and stipe width was 10mm, slightly tapering upwards. White, and very faintly longitudinally lined, with a yellowish-brown tinge at one-third from base, and a shallow ridge near base. Smooth towards apex, more granular towards base.
Smell: not particularly strong, tangy mushroom aroma.
Reference
Bednar, R., Cervenka, J., Arendt, D., Szaboova, D., Krisai-Greilhuber, I., Posta, A., Medic, A. and Tkalcec, Z. (2022) Coprinopsis alnivora (Psathyrellaceae), a rare species from North America is discovered in Europe. Phytotaxa, 542 (2), 136-152.