Saturday, March 26, 2011

The trouble with lichen ...

There is a joy in learning new things and exploring the small mysteries lurking in my own back yard.

What starts with a fascination about the a wondrous tiny thing, morphs into an adventure in learning.

Bottlebrush Shield lichen and  Boreal Oakmoss lichen

Take lichen for example.

It started innocently enough when I identified the British Soldier Lichen, which I think looks more like its nic name of "matchstick lichen". 

British Soldier lichen

That lead to the inevitable, "What is / are lichen" ?  

Answer:   Lichens are a pretty weird form of life.   Each lichen species is symbiotic association of two and maybe even three distinct species of organisms, specifically, fungus, algae and sometimes a photosynthesizing bacterium. 

A what ?

Some researchers aren't so sure that the association is that amicable. Some think it's closer to parasitic on the part of the fungus, but there does seem to be an advantage for each organism.

The algae part of the partnership could be chums with a different kind of fungus and form a different lichen or could even live on its own, but the fungus is stuck with just one kind of algae and does not do well on its own. 

Awwwww. Poor fungus.

I came across this marvellous analogy regarding the relationship between the fungus and the algae:

"What lichens do is almost like merging a shrub with a dog to produce something that looks and lives unlike either shrub or dog!" *

Sorry.  Couldn't find a picture of a dog / shrub hybrid but will keep looking.

Some lichens are leaf-like in appearance; others are like a crust (like the stuff you see on rocks)  others have shrubby forms, and to further confuse us, there are also gelatinous lichens.

 So to clarify, it can be leafy, flat, soft, hard, flexible, stiff, thin or bushy .   Any questions ?

A lichen gets most of its nutrients from air and from moisture in the air.  They do not harm the trees that they are living on. 

Acid rain and air pollution have a devastating effect on some lichens.  Like the canary in the coal mine, the presence or absense of  certain lichens is an excellent indicator of pollution levels.

We have many varieties of lichen here in Nova Scotia which says something about the air quality in our under-populated little province.  

Lichens can live on live trees, dead trees and on rock.  

I'm impressed.  Nothing else can live on a rock !

One of the rarest lichens is the Boreal Felt Lichen (BFL) was once found throughout the Northern Atlantic regions of Europe and North America.  Today only small populations of it remain in Nova Scotia and Newfoundland.  It is thought to be extinct in all its previous locations.  The cause of its extinction is believed to be pollution.

My chum, Amy-Lynn and I spent a fun afternoon last week searching the wood behind her house for BFL.  Read her post about it here:

This week we're going to check out my my woods.

You're welcome to join us. 

* Quote from:


  1. Count me in for the walk in the woods next week........I wish! What a fascinating post Sybil. There seems to be a lot of blogging on lichen at the moment. What's going on? I now feel obliged to do some ferreting of my own. Watch my space! Miss you and Amy-Lynn very much.

  2. I get so many customers coming into the garden center with samples of lichens clinging to a branch of something from their yard. "What can I spray on this to keep it from killing my (insert plant name here)", and this is where I tell them about lichens and why they should worry about something else and how it means the air is not as bad as it could be.

    1. Not sure if you saw my response Les. People can be pretty ignorant about the world around them. What we don't understand we kill.

  3. I wish I could join you since I am also fascinated by lichens. I have many many pictures of them, but few that are as appealing and descriptive as these. I enjoyed your informative narrative as well. You have a wonderful sense of humour. In fact, it seems you are quite a multi-talented gal.

  4. I love the photo of the matchstick lichen (and the writing!). This is a whole new world for me, and I'm looking forward to learning more about it from you and Amy-Lynn.

  5. Les, that's really disturbing that people want to get rid of lichen. It doesn't hurt the tree it is living on. And the lichen has taken so long to grow. I wish people could open their eyes and see it for the marvel it is.

    Missusk76 -- thanks for your kind comments and for stopping by. Much appreciated.

    Farmhousestories -- yep I love the "matchstick lichen". In a monochromatic time of year it's colourful little red head is a standout.

    Thanks too for your optomistic comment about "learning more" ...


Thanks for stopping by. I really do love to read your comments.