Mmm liverworts

I'm part way through an MSc (this one in Biological Recording at MMU) and this year I have to devise and carry out some fieldwork for a dissertation. I'm veering towards mosses and liverworts as I do like them very much (and they have the advantage of being present whatever the season). So whilst on one of our regular Drawing Tours with my sister we stopped at a potential survey site this weekend, a spring at Doulting (near Shepton Mallet in Somerset).

St Aldhelm's Well (CC image by Kerryn)

The water was fantastically clear and cold where it came out of the hillside (the photo above). Then the water ran mellifluously into and out of a stone trough, and down through a grating to run under the road. The stones and walls were smothered in mosses and liverworts. I took some samples which  I will try to identify (when I have a minute, and I'll try to show you how I'm doing it). Some of the liverworts were huge and thallose - I'm sure anyone would have been enamoured with them. They looked rather like this, branching across the surfaces:

CC image by Jason Holinger

Incidentally I had an extremely interesting morning yesterday as I accompanied some students on a tour of Bristol Botanic Garden (the glasshouses there had their fair share of liverworts too). I urge you to go as it's actually free if you're a student, and it's fascinating as it's laid out along the latest phylogenetic understanding of the plant world (this is very unusual as Botanic Gardens are usually venerable institutions and switching things round is a pain, but they moved site relatively recently and were able to take advantage of it).

Anyway it was interesting to take a route along the course of plant evolution, and discover how bryophytes and other groups developed in a much warmer wetter era of Earth's history. Plants only evolved seeds when the climate became drier, when reproduction using swimming sperm (for liverworts do have swimming sperm) became more difficult. That was the change from the Carboniferous to the Permian. I could go on... But I won't, I'll just recommend a trip to the Garden.