A Liking for Lichen

Let me come right out and say it: I love lichens. There.

The reason I love them is the same reason so many people hardly notice them (and when they do it’s usually to pressure-wash them off the patio furniture). They’re often small and unobtrusive, but they’re all around us. Whenever you get up close and personal with a lichen, you enter a completely new world. I didn’t need much encouragement to go lichen spotting in the park for one of my 30 Days Wild.

What is Lichen?

At school I was taught that lichens are a symbiosis between a fungus and an alga.  Much later I discovered that although this is broadly true, it’s a bit of an oversimplification. Yes, a lichen always has a fungal element, but it can contain cyanobacteria as well as algae (and sometimes even both).

The extent to which the algae or bacteria and the fungus depend on each other is also debatable. in many cases the fungus seems to get the best part of the bargain, making the algae or bacteria generate nutrients for it through photosynthesis while doing little more than providing shelter. I once read somewhere that a lichen is a fungus which has discovered agriculture, and this is how I tend to think of them.

How Lichens Reproduce

If you stop and think about it for a few minutes, you’ll see that the very nature of a lichen makes reproduction a complicated matter. Lichens reproduce both sexually and asexually, but however they’re to manage it, establishing a new lichen means reproducing the fungus and the algae or bacteria. This being the case, asexual reproduction is less complicated, because the lichen can just bud off a neat little package containing both fungal and algal cells. Sexual reproduction via spores results in a new fungus, which must then partner up with algae or bacteria.

Jam Tarts or Fruit Gums?

One thing I love about sexually reproducing lichens is their fruiting bodies. So far, it’s believed that these can be of four different types (I say believed because lichens are still mysterious in certain ways). On my lichen walk I just discovered one type of fruiting body known as apothecia, although in the interest of fairness I should say that others may have been present but unseen by me.  I don’t know all that much about lichens, but I do know that you really need a stereoscopic microscope to get to know them properly.

When I first started using the excellent lichen identification key published by the Field Studies Council, one of the instructions was to see whether the apothecia of the lichen you were looking at resembled jam tarts or fruit gums. Today I found both kinds, as these close-up pictures show (apologies for the less-than-brilliant photos, but I needed to use a high magnification with a small depth of field, and the lichens were on undulating surfaces).

Lichen Fruiting Bodies - 30 Days Wild
‘Fruit Gums’
Lichen Fruiting Bodies - 30 Days Wild
‘Jam Tarts’

Here’s what the ‘jam tarts’ tend to look like in cross section under a microscope. I made this slide a couple of years ago while studying some lichens from Chile, and it shows the structure really well. The fringe-like things under the brownish layer are sacs containing spores. The round blue shapes below are algal cells contained in a layer within the fungal ‘cup’ (or ‘pastry’, if we’re sticking with the jam tart comparison).

Jam Tart in Cross Section - 30 Days Wild

Identifying Lichens

This can be really tricky, because there’s a lot of variation in appearance caused by environmental factors such as the amount of sunshine or pollution the lichen encounters. But, like most difficult tasks, it’s fascinating and rewarding. I’d urge all of you to get hold of a magnifying glass and a set of identification charts and, instead of power-washing the lichens off your walls and patios, to become better acquainted with their complex ways.

To inspire you, here’s a few more of the lichens I found on my walk:

Lichen Flora - 30 Days Wild Lichen Flora - 30 Days Wild Lichen Flora - 30 Days Wild Lichen Flora - 30 Days Wild Lichen Flora - 30 Days Wild Lichen Flora - 30 Days Wild

Where The Wild Things Are (and where they aren’t)

In case you haven’t noticed, today is the first day of June. It’s also the first day of 30 Days Wild, an excellent scheme to get us all outside and having encounters with wildlife every day for a month. I signed up in a flurry of optimism a few weeks ago because I think I’m Liz Bonin. I imagined myself spending June in a birding hide somewhere, or skipping through ancient woodland singing madrigals.

Today it dawned on me that I’m not Liz, and I’m not Michaela Strachan, either. I’m a busy person who lives in a city and works at a sedentary job in another, even bigger city. Even worse, I’m not going to be in the country for the entire month: I’m going to be in (you’ve guessed it) a city somewhere in Europe for about half of it. Where the heck am I going to find any wildlife?

Fortunately, my definition of wildlife is a broad one. If it’s alive and we humans aren’t deliberately cultivating or farming it, it counts as wildlife (this is legit, by the way, because I did biology at college and I should know – honest). It includes plants which have managed to find an existence outside gardens and parks, and the insects, birds and fungi all around us. So all I really needed to do to have my very first wild day was walk home more slowly than usual.

In a walk lasting 50 minutes (as opposed to my more usual brisk 35), here’s what I saw:

Mosses and lichens growing on walls. Some of the lichen was actually growing on some of the moss! Just look at that beautiful yellow colour (I’ll write about that in later blog posts because it’s a bit special).

Moss on Wall - 30 Days Wild Lichen on Wall - 30 Days Wild Yellow Lichen on Moss on Wall - 30 Days Wild

A whole load of overgrown verges just bursting with plant life. There weren’t many insects around since it was fairly cold, wet and windy, but I did see a lot of flowers.

Abundant Plant Life - 30 Days Wild Abundant Plant Life - 30 Days Wild Abundant Plant Life - 30 Days Wild

A derelict school where plants of all kinds had pushed through the cracks in the damaged path, and grown under the fence.

Plant Life Under Fence - 30 Days Wild Plants Reclaim the Path - 30 Days Wild

Quite a lot of slugs and snails (some of which reminded me of a really fun citizen science project that ran a few years ago).

Banded Snail - 30 Days Wild Slug - 30 Days Wild

A tree stump teeming with camera-shy ants and showing beautiful spalting.

Tree Stump with Camera-Shy Ants - 30 Days Wild Tree Stump with Spalting - 30 Days Wild

A wild patch left unmown in my local park. Once again, this was hard to capture on camera, but it was beautiful. The long grasses waved enchantingly in the wind and their numerous awns gave them a pretty, fluffy appearance.

Abundant Waving Grasses - 30 Days Wild

So what are the take-home messages from my first wild day?

1. Wildlife lives all around us, so having a wildlife encounter really is just a matter of taking the time to notice what’s already there. Some of it is so commonplace and familiar that we hardly see it, and some of it is so small that we need to take the trouble to find it. Not much trouble, mind, but some nonetheless.

2. Untidiness equals diversity. I saw far more different plants in untended verges and derelict grounds than in any of the (admittedly lovely) tidy gardens I passed. And I’m sure there were many more insects and other animals keeping a low profile among the chaos than I managed to find.

I enjoyed my walk a lot. Maybe I should do the same activity for each of my 30 days wild, or at least the ones where I’m working. Instead of just plugging in to an audiobook and trudging home at top speed, I’ll take the trouble to notice the wildlife around me at different times of day and in different weather conditions on my walk home. It’ll be kind of an impressionist approach to nature.

How will you be spending your wild June days?