Getting on for 20,000 lichenised fungi (usually abbreviated to ‘lichens’) are known, and nearly all of them have an ascomycete (spore shooter) fungus as the mycobiont. Just a few dozen have basidiomycete (spore dropper) mycobionts, and these kinds of lichens are therefore referred to as basidiolichens. Half a dozen or so basidiolichens are found in Britain, and I saw one of them in early July 2012.
I had gone with colleagues from the Countryside Council for Wales and the National Trust to see some of the work going on to restore upland peat bogs on Migneint, a huge mountainous area in North Wales. Much of the work involves blocking up drainage ditches so that these vast upland bogs remain wet and so act as carbon storage reservoirs. (When peat bogs are drained the stored carbon, comprising dead sphagnum moss and plant debris built up over thousands of years, dries out and releases much of its carbon into the atmosphere as greenhouse gases.) There are many other ecosystem services from ‘healthy’ upland bog habitats, including maintaining vital river flows during periods of severe drought. We are not in drought-worry mode in Wales this summer!
Growing in the sphagnum moss were pale ochre mushrooms that looked quite similar to Loreleia marchantiae, the Liverwort Navel – a small funnel-shaped cap-and-stem basidiomycete that grows on Umbrella Liverwort. These were rather paler, though, and on close inspection I noticed that the fungal fruitbodies were sprouting from green algal blobs on the stems of the sphagnum. They were, I realised, Lichenomphalia umbellifera – something that I had been hoping to see one day. (They are not rare, but they certainly don’t occur everywhere.) The fungal fruitbodies of this species, which some people call the Lichen Agaric, are cap-and-stem gilled fruitbodies related to the waxcaps, Hygrophoraceae.