In September I was privileged to spend a couple of days at Dundreggan with Bruce Ing, the UK’s expert on slime moulds, and one of the best slime mould specialists in the world. I’ve had a long standing interest in this unusual and fascinating group of organisms, and wrote a blog about them last year. I’ve been seeking to get Bruce to do a survey at Dundreggan for a couple of years now, so I was delighted when he came up with some dates for one this year.
Setting off into the woodland near the buildings, we were on the look-out for dead wood, which is the substrate that many slime moulds fruit on. We hadn’t been walking far though when we came upon the scene of a forest feast – an orange birch bolete fungus (Leccinum versipelle) whose cap had been almost completely eaten by black slugs (Arion ater). One of the slugs still had its head inside the cap, while two others looked like they were just leaving, having eaten their fill.
In addition to being an expert on slime moulds, Bruce is also a very good mycologist, and as we walked he pointed out a tormentil plant (Potentilla erecta) that had unusual yellow leaves on it. This he said was the effects of a fungus (Taphrina tormentillae) that grows on tormentil, inducing the plant to produce galls – this was an early stage of development of the galls. Fungi in the genus Taphrina cause galls on a variety of plants with the best-known perhaps being the witches broom (Taphrina betulina) that occurs on birch trees.
I led the way uphill towards a group of Scots pines (Pinus sylvestris), where I knew a large branch had been blown down in a winter storm a couple of years previously. I hoped that it would now be at a sufficient stage of decay for there to be slime moulds growing on it. When we reached the pines, there was no sign of slime moulds at all however, but there were several different fungi growing out of the dead wood of the large fallen branch. I spotted a jelly fungus, and Bruce said it was a species (Tremella encephala) that fruits as a parasite on the brackets of another fungus – the bleeding conifer crust fungus (Stereum sanguinolentum) – which was growing on the log.
There was also a bright lilac fungus on the log, and this was the purplepore bracket fungus (Trichaptum abietinum). This is apparently a common species on dead conifer wood, but I hadn’t come across it before myself. However, because it’s so distinctive, I’ll recognise it again easily the next time I see it! It’s not been a great year for fungi though, and we didn’t see many apart from these on the dead wood, and we hadn’t come across any slime moulds at all so far.
I knew of another, larger group of Scots pines not far ahead up the hill, so walked on to them, and this time we had more success. Almost immediately I picked up a small fallen branch and saw something interesting on it. Looking at it through my hand lens, I suspected it was a slime mould, and passing it on to Bruce he confirmed that. It was a species called Comatricha nigra, and the sporocarps, or fruiting bodies were dark brown blobs, on top of very narrow stalks.
There was another cluster of sporocarps on the branch, and although these were the same species, they were at a slightly later stage of development. The fruiting bodies had burst open, releasing their spores, and a parasitic filamentous white mould (Sesquicillium microsporum) had begun growing over them, as they collapsed down on to the wood. The sporocarp phase of many slime moulds is very brief, lasting perhaps just a day or two in some cases, so it’s a question of being in the right place at the right time to see them.
On another piece of dead pine wood nearby Bruce found an example of a fungus (Polycephalomyces tomentosus) fruiting on the spent sporocarps of another slime mould (Trichia botrytis). This fungus only grows on slime moulds, and I’d photographed it on a related species (Trichia varia) at Dundreggan earlier in the year. The fruiting bodies of this fungus are tiny, and are therefore difficult to get in focus in a single image, so I compiled this photograph from a series of images using ‘focus stacking’ software that I wrote about in a blog last winter.
Meanwhile, I spotted what I thought was a different slime mould fruiting on another fallen branch of a Scots pine. However, when I showed it to Bruce he replied that it wasn’t a slime mould, but a club fungus (Typhula spatulata). To a layman it is perhaps hard to distinguish between what is a slime mould and club fungi like this, but in this case the difference is, in part, the fact that the fungal fruiting bodies don’t have distinct stems and heads, as many slime moulds do, but instead there is a continuity of form from the stem to the top of the fruiting body.
Moving down the slope amongst the group of Scots pines we were in, we saw a large fallen tree, and when we looked closely at it we were more successful in finding a variety of slime moulds.
Bruce showed me one he found on some of the dead wood – a species (Dianema corticatum) that I hadn’t seen before, but which formed interesting shapes with its fruiting bodies.
These were slightly geometric-like in appearance, especially the one in the image at the top of this blog. Around some of the fruiting bodies it was possible to see the jelly-like plasmodium, which is the mobile phase of the slime mould, and out of which the fruiting bodies emerge. Slime moulds have complex life cycles, existing for part of their lives as single-celled organisms, which at a certain stage coalesce to form the plasmodium, which can flow and move across its substrate, reaching an optimum spot for the sporocarps or fruiting bodies to form and release their spores, so that the slime mould has the best chance of reproducing successfully.
On another part of the same log Bruce found another slime mould (Colloderma oculatum), which he said jokingly looked a bit like a poached egg. In this one also, the plasmodium was visible, with the fruiting body rising out of the middle of it, like an eyeball, or the yolk of a poached egg. The similarity to an eyeball is reflected in the specific epithet of this species’ scientific name – ‘oculatum’.
While I was photographing this one, Bruce found another, very different, slime mould (Fuligo muscorum) on the ground nearby. It’s one of the more spectacularly-coloured slime moulds, being a brilliant apricot-yellow colour. I hadn’t seen this species before, but I’m familiar with the closely-related dog’s vomit slime mould (Fuligo septica), which is a brighter, pure yellow, contrasting with the more orange-yellow of this species.
I was fascinated to see how the slime mould had spread around some of the grass stems it was on, completely engulfing them. I could imagine that time lapse photography would be a great way to see how this slime mould moves and flows along the stems and over the ground when it fruits like this.
Bruce told me that it doesn’t remain like this for more than a day or so, before changing colour completely and releasing its spores.
Less than a metre away, he found another patch of the same species, but in a more advanced stage of development. I was very glad Bruce was there, because even if I’d spotted this patch, I would never have guessed it was the same organism, as it was so different. The orange-yellow colour had gone completely, and surrounding the grass stems now was a white filamentous, fungus-like growth, with a hardened black section attached to it – this is the stage when it releases its spores.
This was proving to be the most productive area for slime moulds we encountered during the day, and another different species (Physarum robustum) was fruiting on the log as well. The sporocarps of this species also made an interesting pattern, again almost geometric in appearance, and I began to think of these tiny organisms as artists, creating beautiful shapes for anyone who looked closely enough to see and appreciate them.
While I was photographing these slime moulds, Bruce began taking some small pieces of bark off the different trees in the woodland. When I asked him about this, he said that many slime mould species live just under the bark, especially on dead trees, but are rarely seen. By taking some samples home he would be able cultivate these slime moulds and identify them under a microscope, thereby adding to the number of species known on the Estate.
When we finally moved on from this large fallen pine I spotted an interesting sight on a fallen dead birch. It was the fruiting body of a tinder fungus (Fomes fomentarius) that had grown in two different planes, at right angles to each other. The large section had grown while the dead birch had still been standing, but once it fell over, the fungus had continued growing with several new brackets forming at right angles to the old one, so that the spore-bearing fertile surfaces always face downwards.
On another dead birch a little further down in the woodland, there were some small bright orange fruiting bodies clustered together. This was the small stagshorn fungus (Calocera cornea), which I hadn’t photographed before, although I’ve often seen and photographed the closely related yellow stagshorn fungus (Calocera viscosa). The latter has fruiting bodies that are often multiply-branched, whereas with the small stagshorn they are smaller and unbranched.
As we walked on through the woodland, we didn’t see any more slime moulds, but my attention was drawn by a dor beetle (Geotrupes stercorarius) that I spotted crawling along the ground. This is a common species in the Caledonian Forest, and it is coprophagous, meaning that it feeds on the dung of herbivores, typically red deer (Cervus elaphus) in our area. Its black body, tinged with blue at the edges, made an interesting visual contrast with a patch of glittering wood-moss (Hylcomium splendens) that it crawled over – this is the commonest moss species in the forest.
By this time it was late in the afternoon and Bruce left to meet up with his wife and return to the B & B where they were staying for the night. I continued to wander around in the forest, and I was drawn to an area where there were some devil’s-bit scabious plants in flower. That’s one of the late blooming species in our part of the country, and it provides a vital source of food for insects at the end of the summer season each year. By this time the sun was shining and some bumblebees were flying around, stopping on the flowers to feed.
The next morning Bruce returned to do some further survey work for a couple of hours, and I joined him again then. We took a different route from the previous day, exploring the gorge of the Aspen burn, which is not far from the buildings at Dundreggan. Bruce said there are a number of slime moulds that typically fruit on various moss species in wet shady gorges like this, and almost immediately, we found one of them – Lamproderma columbinum – with its fruiting bodies forming white ovoid shapes that stood out from the sphagnum moss they were on. We continued up the gorge for another hour or so, but that was the only slime mould we discovered there that day.
Bruce left soon afterwards, but it had been a very educational and useful time for me, during which I had learned a lot about slime moulds and had photographed quite a number of species I’d never seen before. A few weeks later Bruce returned for another couple of days of surveying, and I met him again briefly then, although I had other commitments at that time, so I was unable to accompany him on the surveys. He told me that the bark samples he’d collected on the previous visit had been quite productive, and he’d cultured several species of slime moulds from them. He took some more bark samples during his second visit and subsequently emailed me to say that as a result he now has a list of over 70 slime mould species from Dundreggan – I’m looking forward to receiving all the details, and his report, in the near future.
Brendan Hannon says
Thanks for posting this – your descriptions and photos helped me identify a slime mold growing on some moss I’ve been cultivating indoors. Glad to have learned about your website!
Alan Watson Featherstone says
Hi Brendan,
Many thanks for your feedback, and I’m glad that my blog was useful to you in helping to identify the slime mould you found on the moss.
With best wishes,
Alan
Rachel Carroll says
I really enjoyed reading this, thanks. Best wishes, Rachel Carroll.
Alan Watson Featherstone says
Thanks for the feedback Rachel.
With best wishes,
Alan
SteveMcWilliam says
Hi Alan,
Yes, Joan Fairhurst and I knew Bruce well when he lived in Cheshire. Joan and I were involved in setting up the Cheshire Local Record Centre (http://www.rECOrd-LRC.co.uk) and Bruce put on a fungal training day in Delamere Forest for us.
Your Blog is excellent and your photos enhance it greatly.
Steve
Alan Watson Featherstone says
Hi Steve,
Thanks for your feedback on my blogs – I’m glad you’re enjoying them, and that you know both Joan & Bruce.
With best wishes,
Alan
Cvenkel Miran says
Hello, would you consider that this image shows fruiting bodies of Dianema corticatum?
Slovenia, on pinus wood.
http://agrozoo.net/jsp/Galery_one_image.jsp?id_galery_obfuscated=9d6dbc1f83bb478ca3bdad78dd1ed461
Alan Watson Featherstone says
Hi there,
I’m sorry, I’m not enough of an expert on slime moulds to be able to provide an answer to you about this question.
With best wishes,
Alan
Joan Fairhurst says
Alan It was a real delight to read this blog. I can just imagine the enthusiasm the two of you shared and your photographs are spectacular. It would be great to have a display of these photos at Dundreggan.
Joan
alan says
Hi Joan, Many thanks for your comment – I’m glad you like the blog and the photos. Do you know Bruce from when he lived in your part of the country? Thanks for your suggestion about displaying the photos at Dundreggan. I’m intending to do an Ecological Features article about slime moulds at some point – I’m just not sure when that will be!
With best wishes, Alan