A Rolling Stone – A Blog about Lichen, Fungi and Moss
I knew this introduction was going to be difficult because the taxonomy of living organisms is a developing science. We used to have just Plants and Animals, then we accepted that Fungi somehow were neither Plants nor Animals. And then it got more complicated.
Now we have Eukaryotes, with cells that include a clearly defined nucleus – Animals, Plants and Fungi; and single-celled Prokaryotes – Bacteria and Archaea. [I was surprised to find that Viruses, even though they may contain DNA, are not actually classified as living organisms.]
I thought I would look at Lichen, Moss and Fungi, three very basic tiny forms of ‘plant life’ in one blog, but it will be more pictorial than scientific. As a prologue, here are some notes obtained, as always, from Wikipedia. Please don’t take them as absolutely right. Even when scientists agree about anything, which doesn’t happen often, they reserve the right to change their minds and disagree in the future.
I used to think that lichen were very elementary plants, the only plants to survive in the frozen North, providing food for reindeer. Well they are generally tiny and insignificant but they are not simple and they are not exactly plants. Each form of lichen is a composite organism composed from Fungi and Green Algae (or Cyanobacteria) in a symbiotic relationship. The lichen form is different to both of its component organisms.
Lichens come in many colours, sizes, and forms. Their properties are sometimes plant-like. Sometimes they have names that include the word ‘moss,’ but they are not related to mosses or to any other plants. They do not have roots and they produce their own food by photosynthesis. They may grow on plants but they are not parasites.
Algae, generally divided into Green Algae and Red Algae, are not easily defined. You will have noticed that I missed them out above. They are Eukaryotes that use photosynthesis, but are not true Green Plants. Sometimes Red Algae, Green Algae and Green Plants are grouped into a more general group of all Plants. Cyanobacteria are bacteria that obtain their energy from photosynthesis – sometimes they are included within Algae!
I won’t attempt to define Fungi, the large group that includes yeast and moulds but are not today considered to be plants or animals. To most of us the well-known ones are the Mushrooms with their fruiting bodies. (No, I won’t attempt to define a Toadstool either.)
Mosses are very small non-vascular, flower-less plants, often confused with Lichens, Hornworts and Liverworts. I tend to think of all moss as the same – little and green.
That’s enough science and information. What follows are some of my pictures with some layman’s comments.
I never really noticed lichen until I started doing photo-blogs. I first noticed it on trees and hedges.
The lichen becomes noticeable in the winter when the leaves have gone. It makes the tree look dead but I think the relationship does no harm to the tree.
Then, when I looked at Walls I noticed that these were often partly covered in lichen of various colours.
This is on an old wall in the countryside. I wasn’t sure whether the orange-brown patch was another lichen or just a fungus so I put the picture on Facebook. Well, apparently the white (possibly Caloplaca teicholyta or Diploicia canescensare), orange (Caloplaca flavescens) and very dark brown patches (perhaps Verrucaria nigrescens) are all lichens – and the right hand side pale brown is a fourth lichen! I won’t do any more identification!
I was surprised to see white lichen on walls in town where I had never noticed it before. These next two pictures are just a few yards from my front door.
The next picture shows a green lichen covering a tree trunk.
I am not sure about the next one, also seen on a tree.
I think it’s a pink lichen but it could be a fungus. (I’m not even sure of the green underneath it. It looks like moss but maybe it’s another lichen.)
The most extensive lichens I have seen have been covering old trees like this.
You will notice that the lichen forms a horizontal band. In this case it comes above a band of moss.
Next we have a very definite yellow coloured lichen.
All my examples so far have been on trees or walls. This last one shows two varieties of fungus on the edge of Boscombe Pier. I am not sure whether they like the salty sea air or just tolerated it.
I can see why moss and lichen are sometimes confused with each other because they grow in similar habitats and are both fairly nondescript. But moss is generally greener and a bit more lush.
Here are two old country walls covered in moss.
And a moss covered tree. I think the tree just provides a habitat. The moss is not parasitic.
Sometimes you can find extensive areas of almost grass-like moss on the ground under trees.
I suppose the moss gradually grows upwards and often it forms a ring around the bottom of a tree in much the same way as some lichen.
But one of the favourite habitats of moss seems to be dead trees. Perhaps when they form they are just low level trees but they are soon covered in moss.
Here are two pictures of walls to show how lichen and moss may cohabit closely.
And another wall top to show that both lichen and moss are hardy – undaunted by coverings of frost.
I have pictures from several places but they all seem to be fungus growing on trees, usually dead trees. There is one I am not sure of but it’s probably a dead tree stump covered by other plants.
Here is one of several examples to show how closely you may see moss and fungus together. It’s easy to associate both with decay on the forest floor but perhaps it’s more accurate to say that both survive in difficult habitats unsuited to flowering plants.
The next picture does not look like a fungus but the tree at Slimbridge has a notice explaining it. It’s called a Witch’s Broom and is caused by a fungal infection on the tree.
Of course we cultivate and eat some mushrooms. Here are some growing rapidly from a do-it-yourself mushroom kit.
A Rolling Stone Gathers no Moss.
This is such a well-known saying and its literal meaning is obvious but I don’t really know what it means as a saying. I always took it to mean that someone who never stays in one place probably doesn’t acquire life-long friends.
It appeared in John Heywood’s collection of Proverbs in 1546. Brewer‘s Dictionary of Phrase and Fable of 1870 also credits Erasmus, and relates it to other Latin proverbs It appears that the original intent of the proverb saw the growth of moss as desirable, and that the intent was to condemn mobility as unprofitable. So says Wikipedia.
[I know you were wondering about the Rolling Stones. Their name was derived in a fairly random way from a blues song Rollin’ Stone recorded by Muddy Waters in 1950.]
I am going to end with some pictures I have saved until last. These are from a tree in the Forest of Dean. They are much more extensive lichen formations than I have seen anywhere else – maybe enough to keep a reindeer going for a while!