Lichen identification

CC image by Jim McCulloch

Lichens grow on all sorts of substrate - bark, wood, stone, soil, even moss and other lichens. This is a useful identification feature. You can collect many species just from twigs -  the Field Studies Council have produced a guide. We have copies of this you can borrow, and similar ones for other lichen habitats. They're very cheap if you want to buy one. The reverse has a lateral key which encourages you to look at the lichens' forms and introduces you to some of the descriptive terminology.

I think it's very good. But the pictures are quite small, and it's nice to have a reliable alternative to check against. I think Alan Silverside's lichen pages are an excellent online option once you've got an idea of what your species or family might be. His photos are very clear and come with a detailed description of the species. Mike Sutcliffe's British Lichens site is also a reliable place to look for photographs.

You might want to have a look at this 'Key to Nature' online key for lichens on twigs in England.
It's been developed by Reliable Lichen Experts so should work well. Alternatively the same authors have written a printoutable similar key which you can download here.

Luxuriant Scottish Usnea. CC image by Nick Rowland.

The Lichen Bible though is Frank Dobson's book 'Lichens - an illustrated guide to the British and Irish species'. Once you've had a go with the FSC guide you should really brace yourself and look at this tome. There's a copy in the library and we do also have a couple of copies you can borrow. It's got detailed descriptions and several types of key. (If you remember, you must show in your field notebook that you can run species through the key). At first you might feel overwhelmed, but it's logically set out - and most of the species will be irrelevant to your own mystery lichens at the moment, since many are rare or restricted geographically or by substrate. I'm not claiming to be an expert, but if you arrange to see me, we can look at the key together and I can give you some help.  (It's certainly not cheap, but if it turns out you have the lichen bug you might want to buy a copy - though beware, old editions have black and white photos not colour).

An interesting thing about Dobson is that he includes chemical tests where they're relevant. This can be a real boon when you're in a lichen-identifying dilemma. There aren't tests for everything, but they can be really useful in confirming or denying your hunch and choosing between similar-looking species. There are three main chemicals (which I can provide), and if you get really into it there's even the option of cutting sections, making slides and adding other chemicals to them whilst looking down the microscope. Am I getting carried away? Very possibly. Most of this is not necessary unless you get super keen.

Read on for information about  how to label and present your specimens.

Harris Tweed, made in the Outer Hebrides, was traditionally dyed with Parmelia lichens. They gave it a distinctive smell! Image by PKM.