I recently took this photograph when sweeping up the leaves on my back yard. I hadn’t previously taken much notice of the lichens on my acer tree, but on that day the sun’s reflection made them stand out like a miniature coral reef. Perhaps it’s the more dominant autumn leaves that cause us to overlook these small organisms but if you look carefully at this time of the year you can see them all over, from trees to gravestones.
When volunteering at Urban Nature I was made aware that an oak tree, for example, lived in association with 284 insect species and 324 lichen species. Apparently, lichens are not parasitic, so they do not harm the trees or plants they grow on. In addition, they are useful to other wildlife, providing material for birds’ nests as well as food and shelter for bugs and small creatures. I enjoyed researching their use in birds’ nests, particularly their use by long-tailed tits, families of which tweet their way across my garden.
I’m not sure whether the birds have a particular favourite lichen, but some of the names that caught my eye included Tree lungwort, Octopus suckers, Blackberries in custard, Floury dog-lichen, Bloody heart lichen, Stinky stictus, and Lob scrob. I imagine that there might be an occasion when you would take some satisfaction in calling someone a “lob scrob”.
Lichens are also useful to humans in their pharmaceutical use for sunscreens, wool dyes and perfumes. According to the charity Plantlife,
the biology of lichens brings so much potential for humans, including the treatment of cancer. The old-man’s beard lichen contains usnic acid, which is considered more effective than penicillin against some bacteria,
but researchers have only just touched on the capacity of these organisms.
Extracting water and nutrients from the air, lichens are also important indicators of a healthy environment. Lichens simply cannot survive without good air quality, so you might want to have a closer look at your garden to see if it is an improving environment.
By volunteer, Paul Freeborough