We love our Sphagnum in Wales, we certainly have a lot of it, and every year at North Wales Plant Group we have at least one Sphagnum session to make sure our ID skills are tip top! I went to the indoor session to chew over some slightly awkward specimens with the group and generally refine my ID.Sphagnum species are often considered difficult by novice bryologists. I don’t think they are that bad, but then Sphagnum was the first group of mosses I ever tackled, and I have had the benefit of being taught by the legendary Martha Newton, which I’m sure must help in demystifying this group of plants. The thing to remember is that this is moss we are talking about. It is perfectly OK and normal in the moss world if you need to take something home and check it under the microscope. Once you realise you aren’t expected to identify everything confidently in the field, the pressure is off.
I definitely recommend using a combination of the field key and microscope for identification. Why struggle for ages dithering about stem leaf shape when you can just put a leaf under the microscope and see whether it has fibrils or not ? These sessions are really helpful because someone always brings a funny coloured specimen, or something that’s a funny shape. Brown Sphagnum subnitens is a classic, as is Sphagnum palustre pretending to be Sphagnum papillosum, or Sphagnum inundatum masquerading as green Sphagnum fallax until you see the stem leaves. Sometimes it’s helpful just to be reminded that Sphagnum species can look rather alike at first glance and it’s always a good idea to have a quick check to make sure.