Inchnadamph (Part 2)

 As promised, here is a bit more about the week at Inchnadamph.  On Thursday, we went to the coast to a beach called Clach Toll.  As I live 45 miles from the sea, coastal lichens are another group that I am not overly familiar with but there were plenty of helpful friends to point out interesting lichens. The day was windy but dry, and the views wonderful.

Clach Toll Beach

However, as warned in the last post, it took a while to get out of the car park! This was partly because there was a small hut with beach finds to look at and also some whale bones mounted at the side of the car park.  A notice said they were from a Fin whale that had been stranded on the beach. One of the bones was misidentified on the notice as a skull, when it was clearly a vertebra.  This did not escape the notice of two of the party who were pathologists! Bone is just another surface that lichens can make a home on.

Examining a whalebone

After a brief visit to the public toilet (more lichens on the brickwork!), we went down to the beach.  The red rocks were Lewisian gneiss which is 3.1 billion years old.

One coastal species not found far inland was Anaptychia runcinata which looks brown when dry but turns green when sprayed with water.

Anaptychia runcinata: dry (on left) and wet (on right)

Some snails had found a wet crack to huddle into away from the drying breeze.

Snail haven (heaven?)

 There was a stop for lunch (First rule of field work: never be separated from your packed lunch!).

Lunch on the rocks.

Round the corner from this lunch spot, I found a place where water ran down the rocks. This was mainly inhabited by jelly lichens (which I usually just admire and then move on, as I find them hard to ID),  but there was something I recognised at the top -  a cluster of small spotty lobes of Dermatocarpon miniatum.

Jelly lichens bracketed in red. Dermatocarpon circled in blue and shown in close up.

On Friday, I went to the graveyard at Elphin, just a few miles down the road.  I was ill-prepared as I forgot my phone (which I use to take pictures of the lichens I find). However, one of the group took some photos for me (and of me as it turned out).

The lichen I was interested in was the white one with black spots (apothecia).  The white one just above it is Ochrolechia parella or crab eye lichen. It has large apothecia with thick margins  and is one that you can name just by looking. The one with black spots could be lots of things so I took a small sample  and looked at it under the microscope when we got back.

The first job was to mount the small sample on a microscope slide to keep it still while I sectioned it - i.e. cut a thin slice so I could see the inside. Then the slice was put on another slide in a drop of water, covered by a thin square of glass (a cover slip) and put under the compound microscope where light was shone through it to reveal the inside structure. The see-though area is where the spores grow. The photo shows the three stages.

Sample - section - spores

The spores are the bobbly looking shapes on the right hand side of the photo.  Once you have spores, the next steps are to measure their length and width and to note the structure. The size was 30 x15 micrometres (written µm, pronounced microns). The structure is hard to make out, so the next step was to stain them so they are more visible.  This is done by adding some KOH, then fountain pen ink, then white vinegar.

spores

Now the spores are dyed blue and you can see that they look rather like squashed blackberries or hand grenades. (The big circle is just an air bubble.) This structure is termed muriform, meaning it is like a brick wall. This information led me to an ID of Rhizocarpon reductum (now renamed as Rehmia reducta). This is quite a common lichen, but it can appear in many different forms so it fools me every time! 

Another example of how the same species can appear in different guises, was seen when I sampled a lichen on a wall near the Lodge.

 The darker brown lichen on the right is Fuscidea cyathoides which is quite common on rocks, often forming mosaics. I thought the lighter brown lichen on the left might be a different species so took a sample to look at the spores.

Bean shaped spores, in water (left) and after applying KOH and Iodine (right)

The bean shaped spores meant that the lighter thallus was also Fuscidea cyathoides. As well as peering through microscopes in the evenings, we also had a couple of talks when people explained what they were working on. Josef (who had driven for 3 days from the Czech Rebublic to join us!) told us about his expedition to Scandinavia looking at lichens returning after glaciers retreat, and Dylan told us about his Ph.D. project collecting environmental DNA and comparing lichen species gathered this way with visual surveys. It wasn't all lichens though. One evening some of us had a delicious dinner out in Lochinver.

On Sunday, it was time to drive home and the weather turned dry and sunny!