Lichen-not what it seems

These Lichens were growing on the old bricks high up on the roof of Oxburgh Hall.

There was a group of historical re-enactors at the hall and earlier I had spoken to the brick maker. All the bricks were made on site and the hall took 20 years to build. These bricks were a perfect habitat for some crustose lichens.

Lichens are literally everywhere, they can be found on high mountain rocks , they grow on trees , they can even be found in the Arctic. Once you key into them you notice them everywhere, on the seat at the park , by the bus stop, anywhere.

They are good indicators of pollution and only certain species can tolerate different levels of pollutants.

Some Quick Facts:-

There are 1,700 species of lichen in Britain
18,000 species have been identified worldwide
Some colonies are 9000 years old !

Interestingly lichens are not one single organism. They are actually a close partnership between a fungus and an alga . They are so closely interwoven they appear as one organism. Here are some great diagrams to explain that structure and also how lichen can be different shapes.

The algae that are part of lichens can be found on their own as free living species. The fungal partners of British lichens are recognisable but can only survive with an algae partner.

There are 1,500 genera if algae in the world but only three genera make suitable lichen partners.

Trebouxia
Trentepohlia
Nostoc

These are common , the same algae can combine with different fungi to produce entirely different lichens.Most lichens contain only one type of algae.

How about identifying these lichens from Oxburgh- they are definitely crustose in form these cannot be removed from the substrate ( the rocks)

The yellow ones could be Caloplaca aurantia/flavescens. I need to take closer photos and more observations next time to make a better identification.

The white pale grey – Ochrolechia parella?

I am fascinated by these organisms and will be out and about learning to identify them with a new field studies councils guide.I’m off to buy one to add to my collection. These are brilliant , only £3 and they fit in a coat pocket or rucksack.