Split Gill

Cardiff Council seems very keen on cutting down trees in its parks, sometimes on what seems like the flimsiest of reasoning. As an example, the children's playground in the park closest to the Boy Wonder's home used to have a large willow tree at its centre, which provided welcome shade in an otherwise open area, but when the playground was resurfaced and upgraded last year the tree was cut down, leaving an ugly stump (which is now, of course, sprouting in all directions, because willows), and no shade whatsoever. I could have forgiven this more easily if the upgrade hadn't also included the installation of several huge boulders around the small children's climbing equipment, which have the words "skull fracture" lighting up in flashing neon letters in my head whenever I set eyes on them.

The up side of this rush to destruction is that the park keepers don't grind out the stumps of the felled trees, but leave them to rot, providing food for fungi and shelter for invertebrates. On a day when the Boy was "not inchrested" in having his photo taken, I left him and R at the swings and took a rapid trot around the inner section of the park, and within a couple of minutes had spotted clumps of Sulphur Tuft and Rustgill, some Stump Puffballs, and these, which I believe to be Schizophyllum commune, or Split Gills. If I'd had a dental mirror with me, or been able to turn over this root, I could have obtained more evidence - the underside of the Split Gill has folds radiating out from the attachment point, which look like gills though strictly speaking they're not - but as it is my identification is based on probability. If I can remember to take a mirror with me next week, and then remember exactly where these were, I'll take another look. ("If" doing quite a bit of lifting there.)

The Split Gill is an extremely common mushroom, found throughout the world on dead and diseased hardwood trees. Possibly because it's so common, it has been extensively studied. One lengthy study by scientists from Harvard University established that specimens from different regions of the world can breed with each other, but also showed that the Split Gill has an extremely complex mating system, requiring specific compatibilities between the joining cells if a fruiting body is to be produced. This system, which has evolved to maximise the genetic diversity of spores, is described in technical detail by Wikipedia, and less technically by Pat O'Reilly if you'd like to read more.

Another more recent study has looked at the electrical impulses that travel through the mycelia of different fungi. These impulses are conducted along filamentous threads called hyphae in a way that has been compared to the transmission of nerve impulses in animals, and it has been suggested that spikes in this electrical activity might even equate with human language. A team from the University of West England conducted research on this and published a paper last year in which they described a "vocabulary" of impulse spikes in the four species of fungus they studied, among which the Split Gill appeared to be generating the most complex "sentences". Unsurprisingly, The Guardian reported some scepticism from other mycologists towards this theory, but as long as I'm wearing my least sceptical hat, I confess that I find the romance of it appealing. I also love the fact that the research was carried out by a team from UWE's Unconventional Computing Laboratory - an organisation that sounds as if it was dreamed up by Terry Pratchett.