Dear Readers, back in October I shared the story of St James’s church in Langua in Wales, home to some of the UK’s rarest mosses, but due to have a replacement roof. The story of how the renovators and the naturalists worked together to make sure the mosses survived was a happy story during a year when it’s mainly been one disaster after another, so you can read about it again here.

Furthermore, for those of you in the UK with access to I-Player, you might enjoy this wonderful documentary about moss, which certainly opened my eyes!

And finally, for those of you who read and enjoyed ‘Braiding Sweetgrass – indigenous Wisdom, Scientific Knowledge and the Teachings of Plants’ by Robin Wall Kimmerer might also like her book ‘Gathering Moss – A Natural and Cultural History of Mosses‘.

And now, let’s have a chat about mosses, these most unobtrusive and resilient of plants.

A series following the 72 British mini-seasons of Nature’s Calendar by Kiera Chapman, Lulah Ellender, Rowan Jaines and Rebecca Warren. 

Dear Readers, I’ve always had a soft spot for the small, unobtrusive plants and animals that live amongst us, going about the business of photosynthesising or munching up detritus while being studiously ignored by everyone except the very young, or the very curious. So I was very happy to see that this mini-season featured moss. As the author, Kiera Chapman, points out, when there are other, more flamboyant plants to attract our attention the delicate beauty of moss is easy to overlook. But it has been around for a long time, and it grows in locations where nothing else could possibly grow.

Mosses are non-vascular plants, which means that they don’t have the internal pipework that allows them to transport water and nutrients through their bodies. Neither can they stand up tall like a tree. Instead, they inhabit very particular microsystems, generally ones that are damp, as they can’t just find water deep in the soil and use it as plants with more developed root systems do. They like areas which are calm, and which have lots of water vapour – look closely at where mosses grow, and they’re so often in cracks and crevices, on the sides of trees that are protected from the prevailing wind, and which allow them to husband any water that they can find. Some mosses, however, live in places where water is fleeting and the area where they live dries up at certain times of year. You might think that this would be a death sentence, but no – some mosses can survive being desiccated by 85 or even ninety percent, only to revive when the rains come.

Some mosses, of course, live in places that are not just a bit on the damp side, but positively wet, such as sphagnum moss which is the backbone of a bog. It is this moss which forms a key ingredient of peat, which is fortunately, finally, being recognised as the important carbon sink that it is. Sphagnum moss has an extraordinary ability to soak up fluids, and it was used as a wound dressing during World War I – not only was it more absorbent than cotton, it also seemed to have a microbial action which meant that it could be left longer without needing to be changed.

In the photo below we see the UK’s largest moss, Common Haircap moss, with sphagnum moss in the background.

All mosses, like all frogs, need water to reproduce: they produce spores, but the male sexual cell needs to swim in order to fertilise the female cell in the first place. In order to spread their spores, the mosses need an area of more turbulent air in order to distribute them, which is why many mosses produce their fertilised spores on setae, long stalks.

Some mosses also have the ability to catapult their spores up to eight inches away from the plant, which is quite some feat when you consider how small the moss is.

Chapman points out that mosses are indeed ancient plants, but they are far from being relicts: they have adapted to live in the harshest of environments, which our walls and pavements and buildings certainly represent. But in a talk by Jeff Duckett, who was describing the changing flora of Hampstead Heath, he points out that mosses and liverworts are reliable indicators of the levels and types of air pollution, and the moss and lichen population of London changed greatly after the Clean Air Acts in the 1960s. These days, some mosses are taking advantage of the nitrous oxides produced by cars – the nitrogen-loving marble screw moss hated the sulphur that used to foul London’s air, but are quite happy with the products of car exhausts.

 

What’s always interested me about mosses is the way that they make tiny microhabitats. If you look closely you can often see other plants growing with and through a mossy spot, and little invertebrates hurrying about their business. These are miniature worlds, full of interest and complexity. Next time you’re hurrying along an urban street, or strolling through a woody glade, stop and have a look at any mossy spot that you find. I guarantee that you’ll find something to surprise you.

For more on mosses, here’s a piece that I did following a talk at the Natural History Museum a few years ago. It’s what really got me interested in these plants. Plus there’s an amazing Theodore Roethke poem at the end, for those of you who are poetry lovers….