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Lichen Foray, Hutton Buscel, October 10th

Instead of our traditional fungus foray, we had a trip with a difference this year, looking at the lichens in Hutton Buscel churchyard. We were delighted to welcome some visitors from Scarborough, including Colin and Beryl Stephenson (so it turned into a bit of a fungus foray as well!).

Don handed out a list of all the species known to occur at this site, a very impressive 67, and we managed to add another six during the next couple of hours (see below). At the entrance to the churchyard Don gave us a fascinating mini-lecture on lichens, and some of their peculiarities: apparently they can reproduce either sexually by spores (although these are only for the fungal partner, which then has to find the appropriate alga when it germinates in order to grow into a new lichen) or asexually by producing a powder consisting of a few algal cells wrapped up in fungal hyphae like a little parcel. This mode of reproduction had become commoner, as a result of pollution; lichens seem to be particularly sensitive to pollution levels, for example acid rain. Later we did see some tough exceptions to this, growing in the “toxic shadow” areas under the windows where iron and lead have washed down. Lecanora conizaeoides tolerates sulphur fumes, and is thought to have developed this ability around the volcanoes of its native Iceland. One or two of the species we saw are normally coastal, including one rather bushy one (Ramalina siliquosa) which is apparently relished by the sheep on Orkney!

Don showed us dozens of different lichens, growing on the churchyard wall, tree trunks, the church itself, the mortar between the stones, and the various gravestones in the churchyard. The substrate is very important, and one of the few things I can remember is that “If it’s yellow, it’s probably Caloplaca and limy”. Certainly where the walls were built of sandstone it was very apparent that there were different species growing on the (acidic) stone and the (limier) mortar. Indeed some species (e.g. Diploicia canescens) seem to be migrating form tree bark to stone. I am afraid that I could not tell the many different species apart, beyond the fact that some were flat and powdery, others were leafy or even bushy, and yet others were fruiting with small cup-like organs, and some did have distinctive colours (yellow, green, blackish, grey, or whitish). Obviously lichen-recognition is a highly-skilled business, or possibly a black art. It was most impressive to see Don smear a drop of “magic liquid” (in reality either potassium hydroxide (KOH) or chlorine-rich household bleach) onto a particular species and have it change colour dramatically, just as he said it would.

So, a fascinating and educational trip – but I think I will stay with flowers and birds for the moment!

I did not make a full list of other wildlife, but we did see or hear some birds (robin, great and blue tits, treecreeper, house martins, mistle thrush, wren and collared dove) and see a few plants in flower (ivy, daisy, dandelion, broad-leaved willowherb, herb robert, smooth sow-thistle, broad-leaved dock, chickweed and groundsel). There were a couple of ferns (wall rue and spleenwort) growing on the wall along with feverfew, and a large patch of butcher’s broom just inside the gate was interesting. We thought it had berries on, but they turned out to be from the yew tree above, and to have got caught on the spiny “leaves” of the shrub. We also saw a hoverfly larva on one of the tombstones, feasting on the abundant greenfly which had presumably blown or fallen off the overhanging trees.

There were a few fungi, but not as many as we might have expected. They included honey fungus, puffballs, a bracket fungus and horse mushrooms.

Gill Smith 11 Oct 2001

List of Lichens from Don: