If this is a week for underdogs (go team GB!) then writing about lichens seems about right. Fiendishly difficult to identify and small in stature, it’s not surprising that they don’t get much of the limelight- but their obscurity seems a little bit unfair once you start uncovering how strange and wonderful they are.
Lichens are unusual in that they’re actually made up of two (and sometimes even three!) different organisms living together symbiotically- a fungus, an alga, and/or a cyanobacterium. The strategy is thought to benefit both parties- the fungus gets sugars that the algae or cyanobacteria have made through photosynthesis, and the algae/cyanobacteria get a stable environment and access to various chemicals that only a fungus is able to produce. That this happened once in evolutionary time is pretty amazing- but we now know that it happened on multiple occasions, in many different lineages across the fungal tree of life. There are 1700 species in the UK alone, which may go some way to explaining why they’re not exactly mainstream. I know very little about lichen- they’re a new frontier which I’d definitely like to get to know better. I love that they form these tiny Lilliputlean forests which look like they’ve come straight out of a fairy tale- like the one on this fencepost, which made the rounds on twitter a couple of weeks ago.
Inspired by the image, I set off to find a mini-forest of my own around Strumpshaw and Buckenham. I was pretty pleased with my success, finding a variety of species in the wet woodland and lots of egg yolk yellow Xanthoria on some concrete fenceposts. I suspect these won’t be the last of the lichen posts- it was the most fun I’ve had with my macro lens all winter.