obin Wall Kimmerer can recall almost to the day when she first fell under the unlikely spell of moss. “It’s kind of embarrassing,” she says. “I’ve always been engaged with plants, because I grew up in the countryside. That was my world. But mosses I’d set aside in my mind as not worthy of attention. I was studying to be a forest ecologist. That little green scum on the rocks: how interesting could it really be? Only then there came a point when I’d taken every botany class our university had to offer, except one: the ecology of mosses. I thought I’d do it, just so I could say that I’d taken them all. It was love at first sight. I remember looking with a lens at these big glacial erratic boulders that were covered in moss, and thinking: there’s a whole world here to be discovered.” Ever since, she has rarely left her house for a walk without such a lens on a string around her neck. Kimmerer, a professor of environmental biology and the director of the Centre for Native Peoples and the Environment at the State University of New York in Syracuse, is probably the most well-known bryologist at work in the world today. She may be, in fact, the only well-known bryologist at work today (bryology is the study of mosses and liverworts), at least among the general public. But her unlikely success – her fans include the writer Robert Macfarlane and the Pulitzer prize-winning novelist Richard Powers, who gives daily thanks for what he calls her “endless knowledge” – hardly arrived overnight. In 2013, Kimmerer, a member of the Citizen Potawatomi Nation of Oklahoma, quietly published a book called Braiding Sweetgrass: Indigenous Wisdom, Scientific Knowledge, and the Teaching of Plants – a (seemingly) niche read from a small US press. For a long time, nothing happened. Last year, however, it suddenly appeared on the New York Times bestseller list. It has since sold more than 500,000 copies worldwide. Thanks to this, her first book, Gathering Moss: A Natural and Cultural History of Mosses, is now also to be reissued in the UK, no fewer than 18 years after its first publication. Is Kimmerer surprised by these developments? Yes, and no. “There was no marketing push,” she says. “The books were sold hand to hand. I think it’s almost a case of critical mass. But I also think that the times we’re living in are creating a longing for a connection to land and nature: what I call a longing for belonging. Both books provide a doorway to that kind of belonging, and maybe, too, we’re finally coming to value those things that are not entirely tied up with commerce.” This, she believes, could be just the moment for the steadiness and intricacy of moss. “In the pandemic, people talk of lockdown,” she says. “But I like the phrase ‘sheltering in place’, which suggests that we might have come to pay attention to the things that we have, rather than the things we don’t have, spending time in our garden or in the woods, finding solace in landscape.” Looking at mosses close up is, she insists, a comforting, mindful thing: “They’re the most overlooked plants on the planet. But they’re gifts, too. They provide us with another model of how we might live.” Read Kimmerer’s book and you’re unlikely ever again to waste precious gardening time scraping moss from paving stones. You may even find yourself trying to encourage its growth. As she reveals, beneath your feet, barely visible to the eye, is another world: a rainforest in miniature, though you’ll need to fall to your knees to see it properly. (At the scale of a moss, walking over it is like flying over a continent at 32,000 feet.) The most primitive of plants, mosses lack flowers, fruits and seeds, have no roots, and no vascular system to conduct water internally, and yet there are 22,000 species, even if most are still so little known to the public that only a few have been given common names. The undisputed masters of their chosen environments, mosses succeed by inhabiting the places other plants cannot. “We’re busy looking for biological, ecological and cultural solutions to climate chaos,” says Kimmerer. “But mosses, which have been with us ever since they arose, 400 million years ago, have endured every climate change that has ever happened.” Quite apart from what she regards as their unique beauty, their mere existence should, she thinks, lead us to ask certain questions. Why are they so resilient? What can they teach us? What secrets might they hold? Can mosses help us to read the state of the planet? “We don’t know if they can in macro ways,” Kimmerer tells me (she’s speaking to me on Zoom from upstate New York). “But in small ways, yes. They are great indicators of air quality, and of heavy metals in the environment; because they have no epidermis, they’re intimate with the world. They’re storytellers. If I see a certain kind of moss, I’ll think, Oh, I know you… you wouldn’t be here unless there was limestone nearby. There are mosses that tell the story of land disturbance, and there are mosses that only come in after fires, and they’re habitats, too, for tardigrades and rotifers [minute aquatic animals], for algae, and all sorts of other things. They are the coral reef of the forest, a microbiome in which the species of the bacteria that live in the angles of their leaves are different, say, to those on their rhizoids [the filaments found on their thallus, or plant body].” Mosses can reproduce in more than one way – via spores or, in extremis, by means of cloning – and they tolerate stress like few other plants, going into suspended animation when conditions aren’t right. A moss can lose up to 98% of its moisture and still survive to restore itself once the supply of water is restored. Even after 40 years of dehydration in a musty specimen cabinet, mosses have been fully revived after a quick dunk in a Petri dish. “This is a primary adaptation to their role as the first colonisers of the land,” she says. “There was no soil here then – nothing for roots to grab on to, and no way to conserve water – so this was an evolutionary imperative. It’s quite remarkable, though not all mosses have it. Others have evolved to live in continuously wet places.” In Gathering Moss, Kimmerer attempts to trace the hidden history of these ancient plants (so little has been written down). Northern people, she discovers, traditionally lined their boots and mittens with soft mosses for insulation. Carolus Linnaeus, the so-called father of modern plant taxonomy, reports that he slept on a bedroll of portable Polytrichum moss as he travelled among the indigenous Sami of Lappland. Pillows made of Hypnum mosses were said to induce special dreams in the sleeper. Fishermen once used moss to clean freshly caught salmon. Most amazing of all, moss was often used for nappies and sanitary towels: as Kimmerer notes, Sphagnum moss can absorb 20 to 40 times its weight in water, a feat that easily rivals the performance of Pampers. Has all this given her any clues as to how moss might be used in the future? They are, alas, not good to eat (she has tried). But a lot of research is currently going on into their secondary chemistry, including their antimicrobial capacities. “This makes sense,” she says. “Because they have long been a part of traditional medicine.” Does she have a favourite moss? Is it, perhaps, Schistostega pennata, otherwise known as goblin’s gold, a moss she describes in her book as “a paragon of minimalism” for its ability to live in caves with little natural light? (It makes use, not of leaves, but of a fragile mat of filaments known as the protonema, and seems almost to shimmer in the gloom.) Kimmerer laughs. “That’s a hard one,” she says. “But I think it would be Tetraphis pellucida, a moss that hedges its bets reproductively [growing almost exclusively on rotten stumps and logs, it has uniquely specialised means of both sexual and asexual reproduction]. I love them. Their architecture is so beautiful.” In her book, she describes her efforts to inventory the individual shoots in Tetraphis colonies – a dense colony can have 300 shoots per square centimetre – marking each one with a bright pink plastic cocktail sword so she can find it again when she returns the following year (from this process she learns huge amounts about the moss’s life cycle). She likes to imagine the baffled conversations of the hikers who might stumble on these mossy logs, bizarrely decorated with swizzle sticks. It is moss, she tells me, that keeps up her spirits when it comes to global heating. “It’s going to be 100 degrees upstate today,” she says. “That’s wrong, though these extremes are no longer out of the ordinary. We expect them. Of course I worry that people are not going to do what needs to be done; that we’re already too late. But I have faith in photosynthesis. The plants know what to do. They know how to sequester carbon. They know how to cool the air. They know how to build capacity for ecosystem services and biodiversity. Will the world be different? It will. Will there be tremendous losses? There will. Heartbreaking losses. But the evolutionary creativity of the plant world will renew itself. Plants will figure out how to come back to a homeostatic relationship with the planet.” Even as she notices the alarming fact that bloom times are arriving ever earlier, she is also increasingly aware of the natural movement of plants: “We’ve fragmented the planet in such a way that their natural migration routes are broken up. So it’s our responsibility now to assist that migration, to essentially help forests to ‘walk’. We have to help them get to where they need to go.” Will we be here to witness a new world, the one that she believes will be regenerated for us by the plants? She hesitates. “I have less faith in that.” The engine of her next book will be “ecological compassion” for plants. She would like people to come to understand them as sovereign beings in their own right, if not people. “The research in plant intelligence that is being done is already revolutionising science,” she says, “so my next project is designed to elicit in the reader a sense of compassion and justice for them. I would like people to recognise their culture. Take off your anthropocentric lenses, and you will see that they have very rich cultural lives.” Do plants have rights? Should they be given more protection under the law? She smiles. “My greatest hope for my book is that it will make perfect sense of their rights. Such rights are not for us to bestow. I believe that they have their own inherent rights.”