From loofahs to LEDs

I've been a bit quiet on the blogging front over the last couple of weeks - partly due to having too many assignments to mark and partly because the unusually wet weather has tended to keep me from doing much in the way of field ecology (this amount of rain is not good for most British terrestrial invertebrates). However, yesterday was the first dry day for a while and happily coincided with a wildlife walk I was due to lead for the Southampton Natural History Society.

We visited a conservation-friendly farm and the event provided an opportunity to record mainly invertebrates, but also anything else of interest that we came across - given the weather (and climate change links which I probably won't write much about here - other bloggers will be doing so) and the huge negative impact expected to be seen on British wildlife, records such as these are of great importance, especially when there is so little funding for professional survey work.

As it happens, we did see a reasonable diversity of invertebrates, though only in small numbers, and those that were numerous tended to be associated with wet or at least damp conditions (e.g. molluscs, woodlice, millipedes). One of these was the slime-mould Stemonitopsis typhina...

One of several clusters of Stemonitopsis typhina.

Just as one of my recent posts focused on a slime-mould that looked like a cluster of tiny loofahs, this species reminds me of little pearly-silvery LEDs. Each of the stalked sporangia is about 3-4 mm tall with a black stalk that is no more than half the overall height. Fresh specimens like this are silvery, but can become more lilac-grey with age. It is superficially similar to some of the more cylindrical species and forms within the genus Comatricha (e.g. the uncommon cylindrical form of the usually globular C. nigra) but can easily be separated by the presence of a silvery sheath around the stalk - here this is clearly visible as a pair of pale longitudinal lines running up either side of each stalk, although it actually goes all the way round but is translucent and the stalk shows through. S. typhina is a common and widespread species found on wet, rotten wood, usually of broad-leaved trees, and this example was found (along with several similar clusters) on fragments of sodden and well-rotted willow wood around the base of an old willow tree. A common, if unfamilar, example of the importance of dead wood habitats - more wet-summer observations here soon...