Lichens and Jew's Ears
Do you remember the Observer's Books? I have a few that I bought in the 1960s. They helped me to become more observant - that was their purpose I guess. When I pick them up now I feel pleased that I have them, pleased that I carried them with me on trips but sorry that I didn't value their contents more. Here is an example - one of my favourites.
My interest in lichens was probably sparked by seeing them growing in churchyards on masonry, on paths - lichens are all around. The fact that the various stony substrates in a church yard are often old can lead one to assume that lichens require old weathered materials and lots of time to get established. Thoughts about that later.
Then there were walks in the countryside and lichens were visible on trees, most trees. Wood is a good substrate for some lichens so gates and gate posts host them too.
On The Park, which is a ten year old development lichens are everywhere. The pre-existing trees have them, trees planted in the last ten years have them. The rooves of our house and garage where colonised by lichens, algae and mosses very quickly, probably in the first year. Interesting to note that the species of lichens, algae and mosses are different or absent below the metal flashing. This must indicate intolerance of the 'toxic' metal. My observations on The Park (written about elsewhere) included the lichens growing on trees, in particular on hawthorns. I had noticed the bright yellow/orange and the grey species on hawthorn and managed to identify some of them with the help of my Observer's Book and the excellent Field Studies Council Guides. I knew that I wasn't cataloguing all of the species present as lack of knowledge and confidence made me reluctant to claim some of them. I was aware that lichen are sensitive to and indicators of atmospheric pollution and somewhere in the recesses of my mind I knew that reindeer eat lichen but not the species present on The Park.
Two years ago I was involved in a Parish-wide initiative to survey the biodiversity of The Parish including The Park. The ambition was to improve the number of local records for inclusion in the database of the County Environmental Records Centre. We were very fortunate to have assistance from some of the County Wildlife Recorders all of whom are acknowledged experts on their chosen flora or fauna. That good fortune included a visit to The Park by the acknowledged lichen expert. (He took the opportunity to visit the parish churchyard/cemetery too). These Wildlife Recorders are a delight to meet and watch them methodically recording and sometimes finding species not previously recorded in the area.
The lichen recorder looked at the hawthorn trees that I had previously found of interest. Using a hand lens and a couple of small bottles with test reagents he was able to identify and name 16 species plus two lichenicolous fungi (this is where in addition to the symbiotic life of the fungus and the alga that make the lichen there is another parasitic fungus present on the lichen). The test reagents include an alkali that produces a colour change when applied to the lichen being tested and is part of the identification process. On reflection the colour change is not entirely surprising when you know that the dyes in litmus paper are derived from lichens. Incidentally the species found were indicative of atmospheric nitrogen pollution.
For me the pleasure of his visit was made all the greater when he told me about something growing on all our paving slabs and the brick blocks used in the drive. The something is present on paths and drives all over The Park and is a fungus called Sarcopyrenia gibbi. So what I hear you say. Well this little grey fungus growing in roughly circular patches up to 2cm across is of particular interest to scientists. It has bactericidal properties and interests those working to find new antibiotics.
It has been known for centuries that some lichens are effective in treating bacterial infections. Some lichen derived antibiotics have been used in treating lung disease , and in ointments for burns and wounds . These have been found to be more effective than penicillin. This was known at the time of writing of The Observer's Book of Lichens. The apparently small and simple organisms found all around us are full of surprises and not just something to be swept or washed away.
To complete my blog piece today I would like to say a little about another favourite Observer's Book - The Common Fungi.
Just two things I would like to mention on this occasion. If you have never tried it, you (and family) will be interested to see the gill prints made by taking a conventional capped fungus and placing it with its stalk popped through a hole in a piece of plain white paper. Suspend the arrangement over a cup or similar. Leave it for a day or so and then lift it off to see the pattern made by the spores falling from the gills of the fungus. The colour of the spores harvested this way can be helpful in species identification.
The other thing I want to mention just now is the Jew's Ear fungus Auricularia auricular-Judae. Jew's Ear is so called because of its shape which has a resemblance to a large ear. It is to be found on dead branches . especially of elder, throughout the year. It forms limp somewhat translucent red-brown or maroon coloured fruit bodies shaped like an inverted cup or ear. The Jewish connection is derived from Judas Iscariot and the belief that he hanged himself from an elder tree.
So why have I focused on this particular fungus - well - because it is believed to have bactericidal properties. Once again I reckon we should be slow to dismiss the small or the slightly bizarre little things growing in small spaces. Their potential value may not be immediately obvious. Happy Observing.
