Introduction to mosses

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A couple of days ago I attended a one day course at Woods Mill, the headquarters of the Sussex Wildlife Trust, which was run by our society. Had it been a one day course run by my profession, it would likely have cost me more than £100 and most of it I would have heard before. This, however, cost merely the price of membership to the Sussex Botanical Recording Society and catapulted me almost vertically up what will, I hope, become a very long and enjoyable learning curve.

It was run by David Streeter, our inestimable president, academic ecologist and author of the successful Collins Wild Flower Guide. The aim was to entice us away from a blinkered botanical mindset confined to vascular plants and to spread our taxonomic wings into the paraphyletic (as we learnt) world of mosses, liverworts and hornworts.

We started in the classroom with a general introduction aided by a carefully crafted powerpoint presentation. Britain is more important for bryophytes than it is for flowering plants, having around 60% of the European flora (compared to just 20% for higher plants). Along with lichens, bryophytes are a crucial part of the National Vegetation Classification system, emphasizing their role as habitat indicators.

There are around a thousand bryophyte species in the UK, roughly one third the number of higher plants, and David outlined the general features of the main groupings. Perhaps the striking thing about bryophytes is the dominance of the gametophyte generation, the converse of flowering plants. They are overlooked in general because of their diminutive size, but when you see them close up or through the miracle of magnification they are every bit as beautiful as the flowering plants. Not only that, they are most easily studied in what are usually considered the botanically barren months of the year.

Picture of botanists looking at bryophytes
David Streeter introduces woodland bryophytes. Photo: Nick Sturt

The practical part of the day consisted of a woodland visit and a chalk grassland visit, broken by lunch. We were issued with sheets listing the expected species for each site as well as a very sensible health and safety sheet (which did the trick as there are no accidents to report). For each species we were given the salient features whilst studying them in-hand and many of us kept samples for our records. I found this particularly useful as remembering more than a few new species after a one-off exposure is difficult and consolidation is so much easier with some material to look at again at home.

We spent the lions share of our enthusiasm in the woods, clocking up sixteen species and only stopping when rain provided the necessary cue to return to the classroom for consolidation and lunch. The chalk grassland visit took us to the bottom of Newtimber Hill and we found another six species, along with one which we’d already seen in the woods – Calliergonella cuspidata.

Picture of botanists looking for bryophytes
Bryophyte hunting on Newtimber Hill. Photo: Nick Sturt

I’ve had several ‘go’s at bryophytes but never managed to attain the critical mass of knowledge necessary to serve as a foundation to build on. After this course, followed up with a review at home in front of the books, I feel the world of bryophytes is in grave danger of increased attention. Already I have two samples collected during this morning’s wetland bird survey awaiting.

Reflecting on the experience had me once again marvelling at the generosity of the more experienced members of our society. So many people are prepared to pass on their invaluable knowledge with patience and good humour. It’s inspiring.

Picture of bryophytes in bags
Bagged and identified. Photo: Nevil Hutchinson

Woodland species

  • Brachythecium rutabulum

  • Thamnobryum alopecurum

  • Eurhynchium striatum

  • Polytrichastrum formosum

  • Plagiomnium undulatum

  • Isothecium myosuroides

  • Kindbergia praelonga

  • Cryphaea heteromalla

  • Hypnum cupressiforme

  • Orthotrichum affine

  • Mnium hornum

  • Atrichum undulatum

  • Thuidium tamariscinum

  • Frullania dilatata

  • Microlejeunea ulicina

  • Calliergonella cuspidata

Chalk grassland species

  • Fissidens taxifolius var taxifolius

  • Weissia brachycarpa var obliqua

  • Neckera crispa

  • Entodon concinnus

  • Homalothecium lutescens

  • Pseudoscleropodium purum

  • Calliergonella cuspidata


Mosses and Liverworts of Britain and Ireland: A Field Guide   Ian Atherton, Sam Bosanquet and Mark Lawley (eds)

Mosses & Liverworts – Porley & Hodgetts (Collins New Naturalist series)

British Mosses & Liverworts (3rd Edition) – E.V.Watson (Cambridge)