Identification thoughts

A lichen from yesterday, Hypogymnia physodes, and its weird inflated catpaw lobes. CC image James Lindsey.

I had a nice afternoon yesterday with student T and her extensive lichen collection. We were using a combination of guides and keys and a bit of my prior familiarity with their appearance. It made me think of two things. Firstly, that it's always a good idea to use more than one source of identification. I do love the FSC but even they can't squash everything onto a fold-out guide - lichens are great when they look like they're supposed to, but sometimes they just don't. You might think that's because they're a totally different species and I just can't identify them. But it's not always that. It's because many of them are annoyingly variable. If you went on KL's lichen jaunt around campus the other week, you'll have seen my attempt to make a guide that includes half-eaten lichens as well as pristine ones. It's not even nibbling that's the main problem though - sometimes the lichens look different just because of varying conditions where they're growing (or possibly they do it just because they feel like it, who knows). So, point one, whatever you're collecting, it helps to have a variety of (reliable) descriptions and photos. Hopefully I've given you a few options for your own group in this blog, but I'll keep looking.

Secondly, lots of people have limited transport, so only collect their lichens where they can get to around Bristol. This has the effect of making me look cleverer than I am, because the species they turn up with are generally on a relatively limited list. Nitrogen dioxide and other pollutants limit which can live in the city. So point two, if you can obtain an idea of what you're expecting, it can help. For lichens, the FSC fold-out guides are habitat based (eg urban, heaths, seaside) which is great. And when we were doing the mosses the other day, there were lists at the back of the book for different habitats (it's also online). This is useful as an additional identification strategy (especially with groups where there are many many species in this country).