Liking Lichens

By Karen Banton, Assistant Collections and Learning Curator
* Click on the photos below to visit our Collections Online database and discover more about that object. *
During lockdown, one of the things I’ve had the chance to do, thanks to our John Ellerman Foundation-funded project, is get some of the Ipswich lichen collections onto our online database. This involved completing the documentation of our reference collection of British lichens, also known as the Hitch Collection.
Lichens aren’t something you tend to hear much about, even though you can find them almost everywhere. They aren’t a single being in the way we usually think of living organisms. While some look like plants, they aren’t, and while others look like they might be mould, they aren’t that either!
Lichens are a partnership between a fungi and an algae or cyanobacteria. Why would they form a symbiotic partnership? Well, fungus can’t make its own food, but it can absorb minerals and provide shelter. Algae and cyanobacteria are both excellent at photosynthesis, meaning that they can provide enough food for both themselves and their fungi partner, in exchange for the minerals and shelter it can’t provide for itself.
They grow on rocks, walls, trees and, given the chance, even animal fur… They are an important part of the ecosystem, providing homes for invertebrates, food for many animals and even nesting material.
Getting these lichens online meant I got to look at all the pictures I’d taken, so here are my 10 favourites…
Lobaria pulmonaria

This lichen is known as lungmoss or lungwort. They are unusual because they form a partnership with fungus, algae and cyanobacteria. They grow on trees in ancient woodlands, so seeing them is a good indicator that the wood you’re in is very old. In life they are a bright green. This family of lichens is very sensitive to pollution and Lobaria pulmonaria was once common across the UK and Europe, but is now extinct in many of its old ranges. In the UK it is most common in western and central Scotland, but occurs in other UK areas including Wales.
Even dried out and brown, you can still see hints of how it would have varied in colour by looking up close at the different colourations and textures, from the fine white hair like strands on its curled up edges, to the mottled colour of the underside, to the dark dots that are what remains of the lichens fruiting bodies.
Opegrapha niveoatra

Now these aren’t just any old bits of willow. No, they may not look like much, but a closer inspection (with a microscope) reveals that the speckling on the bark is the fruiting body of a lichen and its powdery looking crust. Those little black strands that cover the rest of the bark are also part of the lichen Opegrapha niveoatra. It’s not the easiest to identify (or spot!) but it just goes to show that if you take a closer look, you might discover that the twig you are holding is more than just a bit of tree!
Pannaria rubiginosa

Pannaria rubiginosa belongs to a group mostly found in tropical regions, but is one of the species that live in the UK! This specimen is one of my favourite lichen because you can see how it’s made a home on some moss. A closer peak shows how it has a flattened surface and its edges are much paler than the rest. Its fruiting bodies are disk like with a white rim, making them stand out from the rest of the lichen.
It tends to grow on mossy bark in old forests and, much like the lungwort, is now found in far fewer places than it used to be, mostly in western Scotland.
Usnea filipendula

This distinctive tangle of strands is known as a beard lichen. Usnea filipendula may look like other beard lichens, but this group is one of the most easily spotted at a distance. Lichens like this grow on trees and would have originally been pale grey before drying out. Its long strands look a bit like hair as they dangle downwards, which is how it earned its common name.
They mostly grow in the north of the UK, and can sometimes be found in the south and southwest, but you’ll need to explore old woodlands to find them.
Acarospora glaucocarpa

This rock is part covered by a lichen known as Acarospora glaucocarpa, also called cobbled or cracked lichen because of its often-overlapping circular growths. They tend to grow on rocks in dry open places. It may not be the most colourful of the lichens on this list, but it’s one of my favourites because of how strongly it contrasts with the rock its growing on. Also, when you get close, it looks like an aerial photograph of an alien landscape….
You ‘ll rarely come across this lichen in the UK, but if you’re somewhere with limestone landscapes, you just might find it!
Caloplaca granulosa

This is one of six rocks that were collected because they were partially covered in Caloplaca granulosa. They were found on the coast in Orkney, Scotland. It’s eye-catching yellow makes it jump out, but I’ll admit, it’s not my favourite example in our collection. Instead, it’s a favourite because of the rock its growing on, which looks a little like a sitting capybara, with the lichen acting as a head covering or hair and nose.
Capybara are the world’s largest rodent and one of my favourite animals so, silly as it may seem, this made my top ten…
Caloplaca granulosa

Now I’ll confess, I hesitated to include a second example of Caloplaca granulosa, but this is my favourite example from the collection. It too was found on the coasts of Orkney but, unlike the previous entry, it gives a better example of just how colourful lichen can be!
Although a closer inspection shows that there may be more than one species on this rock…
Cetraria islandica

Iceland moss is a lichen that grows in solid clumps, giving it a moss-like look. It’s much more solid than many lichens and the leaflike lobes are bordered by spiked edges. It’s striking appearance is the main reason I like it. This one was found growing on the soil of a mountain in Aberdeenshire.
When famines struck, northern Europeans would eat this lichen and it’s considered a ‘culinary lichen’. Not usually on the menu these days, it is used in traditional medicine and in some skincare products.
Dirina massiliensis

This lichen may not look like much, but it still caught my eye and is one of the few lichens collected by Hitch in Suffolk. It’s stuck to some card because Dirina massiliensis is a kind of crust lichen, which means that scraping was the only way to get it off the church wall it was growing on. If it hadn’t been stuck down, the specimen would have crumbled and broken up.
This is the kind of lichen you’ll often see growing on old stone walls. It usually grows in a disk like shape, although can sometimes end up a little more irregular. But this certainly explains why it was stuck onto the card the way it was. Hitch was trying to recreate the disk like growth!
Haematomma ochroleucum

Haematomma ochroleucum is a common UK lichen and can be found all over Britain. While most of this crusty lichen is white or pale grey, it’s spotted with red – these are its distinctive fruiting bodies, earning it’s family the name of bloodstain lichens. This contrast between the main body of the lichen and it’s red spotting is memorable and why it’s one of my favourites.
So those were my top ten, why not have a look at our Hitch British Lichens collection online and see which ones catch your eye?