On Sunday three three of us visited Holt Lowes in North Norfolk. It was very dry and fungi were rather scarce, so we spent most of the time looking at plants. But on a low peaty bank at the edge of the valley mire we found some small, slightly dried out fungal fruitbodies and I brought a couple home to identify.

Lichenomphalia ericetorum

I looked in Volume 2 of Geoffrey Kibby’s “Mushrooms and Toadstools of Britain and Europe” for a possible match and found Lichenomphalia umbellifera.

The species is known as Lichenomphalia ericetorum in The Fungal Database of Britain and Ireland (FRDBI). (Other synonums include Omphalina ericetorum and Botrydina vulgaris.) The species was first described by Linnaeus in 1753 as Agaricus umbelliferus.

The fungus had white spores and decurrent gills. These were widely spaced and sometimes forked and formed veins linking adjacent gills.. When fresh the gills are pale yellowish but in my samples they had dried a darker yellow-orange.  The stipe attached to the centre of the cap and was reddish-brown at the tip. (This colour continued into the lower part of the gills in my specimens.) The base of the stipe was slightly enlarged and covered with a pale fuzz.

Lichenomphalia ericetorum spores look like this:

So far, so normal.

But I found a 2023 blog post by Sim Elliott and the story became much more interesting.

Lichenomphalia ericetorum: Not Just a Fungus, but a Basidiolichen

At first glance, Lichenomphalia ericetorum appears to be a normal basidiomycete fungus but the fruitbody is actually part of a lichen, an association between a fungus and an alga (note 1).

Lichen fungi have evolved independently several times.

Most fungi found in lichens (98%) are ascomycetes (sac or cup fungi) and these give most of the familiar and easily recognised growth forms: a thallus consisting of a colourful crust, a rosettes or a leafy (foliose) or shrubby (fruticose) structure.

A much smaller number of lichens have a basidiomycete fungus as the fungal partner. What we see in Lichenomphalia ericetorum is the fungal fruitbody of one of these basidiolichens.

If you look closely at the base of the Lichenomphalia ericetorum you will see a mass of green blobs. These are green algae in the genus Coccomyxa and are the photosynthetic partner (the photobiont).

Seen under the microscope:

Distribution of Lichenomphalia ericetorum

In Norfolk Lichenomphalia ericetorum had been recorded 30 times from 24 different sites up to the end of 2025.

In the British Isles as a whole there are currently 492 records of Lichenomphalia ericetorum, with a northern bias.

The British Lichen Society website also has a map of the distribution of Lichenomphalia ericetorum but at the time of writing this has no records for Norfolk. (Norfolk records are also missing from my copy of “Lichens” by Frank Dobson (note 2).)

Outside the British Isles, Lichenomphalia ericetorumis found in the northern hemisphere, particularly in the region of the Arctic. It is common in the  Pacific Northwest of Canada and the United States, northward from Santa Cruz in California.

Lichenomphalia ericetorum in Scotland

I remembered seeing some similar fungi a couple of years ago, when Vanna and I were walking the Ryvoan Pass in the Scottish Highlands (note 3).

I found the photos. The Scottish examples were in much better condition than the ones from Norfolk.

At first glance the fungi seemed to be growing in mosses:

But when I looked closely at a second photo it was possible to see the green blobs of Coccomyxa algae more clearly. I’ve cropped the photo to make these easier to see:

I recommend a read of Sim Elliott’s “A lichen that fruits like a mushroom. Lichenomphalia umbellifera at Eridge Rocks. 30.07.23“, which has some good photographs too (from Sussex). The pictures of Lichenomphalia ericetorum on the Lichens Maritimes website (from France and Belgium) are worth a look too.

Notes

Note 1 – Lichens are made up of two or more closely interacting organisms, a fungus, and one or more photosynthetic partners (photobionts).

The lichen symbiosis is thought to be a mutualistic relationship, in which both the fungus and its photobionts benefit. The fungus forms the main structure of the lichen (known as the thallus), which provides a home for the photobionts. These produce simple sugars by photosynthesis, which are used as food by the fungi.

90% of lichen photobionts are green algae and the remainder are cyanobacteria.

98% of lichen fungi are ascomycetes (sac or cup fungi). It is thought that one fifth of all known fungi and half of all ascomycetes are lichenised, with about 28,000 species worldwide.

Note 2 – “Lichens: An Illustrated Guide to the British and Iriosh Species” by Frank S. Dobson. 7th edition (2018, reprinted 2023). The British Lichen Society, London.

Note 3 – The Ryvoan Pass is a lovely 10 mile walk from Glenmore Lodge to Nethy Bridge in the Scottish Highlands. We were staying in a holiday cottage in Nethy Bridge in June 2024 and took a bus to Aviemore and another to Glenmore Lodge. We had bought return tickets but it was such a lovely summer day that we decided to walk the whole route back to Nethy Bridge.

We passed the beautiful An Lochan Uaine (green lochan), headed uphill to the Ryvoan Bothy and through Abernethy Forest. Here we saw Bog Beacon and Twinflower but – sadly or fortunately – didn’t encounter any rogue Capercaillies.