Moss and Lichen by Elizabeth Lawson, 2024. Reaktion Books.

For almost the entirety of its existence the Botanical series from Reaktion Books has been a collection of titles about plants and people, each of which dealt with rather small groupings of vascular – and almost solely flowering * – plants, e.g., genera such as Primula, Rosa, Morus (mulberry), single families such as palms, orchids or composites, or categories of plants, e.g., houseplants, or carnivorous plants. All that changed on 16^th December 2024, with the publication of Moss and lichen by Elizabeth Lawson [which book is here appraised] in the UK. Why? Because Moss and lichen is a major departure from what we’ve previously seen in the Botanical series – not only a move away from vascular plants and towards non-vascular members of the Plant Kingdom, but also extending the series’ botanical reach into another realm altogether, the Fungal Kingdom. Brazenly, botanically bold, how does such a radical – reactionary, even – change from what I’ve – we’ve! – come to expect and respect from that book series fare? [Ed. – for a ‘spoiler’, see **]

 

A celebration of cryptogams…

First things first, mosses and lichens are two such different lifeforms [small, non-vascular land plants, and a combination of a fungus and a photosynthetic bacterium or alga, respectively] that dealing with both in a single book that would read as an integral, coherent whole rather than as a disjointed tale of two distinct halves, would seem to present quite a challenge. But, the book that Lawson created works. In fact it worked so well that it was easy to forget that you are reading a tale of two rather different types of organisms. How did Lawson manage to pull it off? By unifying both moss and lichen under the ‘old-fashioned’ botanical ‘umbrella’ term, cryptogams. That term and fact is introduced early in the book – on p. 8 –  and is firmly embedded in the Introduction’s sub-title, The cryptogamic carpet. Having neatly dealt with that potentially problematic issue, right at the beginning of the book, the reader can just enjoy the rest of Moss and lichen.

Everything you expect from a Reaktion Book Botanical series title***

Moss and lichen compares very well with other Botanical series titles. It has an abundance of illustrations [113, per the book’s back cover, of which 102 are in colour – and some are beautiful as well as informative, e.g. the dehydrated shoot of Sphagnum rubellum (p. 116), and lichen-covered boulders on the shores of Loch Scavaig (p. 94)]. It is very well-written, and nicely phrased – e.g., “They [mosses and lichens] also offered shelter to ancient lineages of microinvertebrates, whose whisperings were the first living voices on Earth” (p. 8), and “It is not known exactly when mosses arrived at Saihō-ji and were allowed to stay by the mossmerized monks…” (p. 202). And it is accessible to, and understandable by, an intelligent readership. Moss and lichen is also a joyous celebration of its subjects.

Its structure is typical of other books in the series. An Introduction, and eight numbered chapters [see more in Did Moss and lichen deliver what I expected? below], and a Timeline [3.5 pages, from “c. 2.7 billion years ago Cyanobacteria (a lichen photobiont) begin oxygenating the planet (the Great Oxygenation Event)” to “2023 Swedish researchers document the decline of the flagship species Usnea longissima, the world’s longest lichen, in both a national park and managed forests …”]; References [approx. 23.5 pages of books, scientific papers, and URLs (with access dates) containing almost 500 numbered items – as per the superscripted numbers in-text – listed by Introduction or Chapter]; Further reading [37 books – at least one of which – Merlin Sheldrake’s Entangled life (p. 244) – is stated as a source in the References section]; Associations and websites [a page and a quarter of cryptogamically-relevant associations and websites, including American, British, Australian, and International organisations concerned with lichens and/or mosses, and the intriguing Ways of Enlichenment [no, this is not a typo…] site]; and an Index [5.5, two-columned pages, from ‘Acarospora socialis’ to ‘Yong, Ed’. Listing, primarily, people (e.g., Hedwig, Hofmeister, Margulis, Shakespeare, Thoreau, Wodehouse), places (e.g., Antarctica, Arctic, desert, Iceland, Namib/Namibia, Royal Botanic Garden Edinburgh), and scientific and English common names of mosses and lichens (e.g., antlered jellyskin lichen, fire extinguisher moss, yellow moosedung moss, electrified cat’s tail moss, mourning phlegm lichen, and Cornish path-moss), it also has a decent number of ’topics’ such as ‘biocrust’, ‘bog (peat bog)’, ‘cyanobacteria’, ‘extremophile’, ‘lemmings’, ‘nematodes’, ‘symbiosis’, ‘terrestrialization’, and ‘vulpinic acid’].

Did Moss and lichen deliver what I expected?

First, as a Botanical series title, Moss and Lichen delivers the expected plant-and-people information. But, and this is much more of an appreciative observation than a criticism, there is a lot more plant biology in this book than one is used to seeing in other titles in the series. There’s still plenty of people dimension – which is what makes these books so appealing, but the great deal of biological material is a pleasant surprise. For the first time I’ve seen a super account of lichen reproduction – with a beautiful diagram to accompany that narrative, which was an unexpected bonus from Lawson’s tome. This book should be recommended reading for all taking any classes in plant biology – it’s eminently informative and readable. As befits its subject matter, Moss and lichen has a lot more about ecology, global environmental issues, and planet-scale matters such as development of a land flora than other Botanical series titles. The first part of the book is largely devoted to those aspects of moss and lichen life, with chapters such as one Curious Vegetation [primarily mosses], two Moss: Versatile Minimalist, three Lichen: Complex Individuality, four Cosmopolitan Extremophiles [both moses and lichens], and five Bogland [primarily moss – and almost 100% sphagnum]. And that’s entirely relevant to the book’s cryptogamous lifeforms which have had such a transformative effect upon the Earth’s surface, and consequently the history of life on this planet, and to their enduring roles in ecological matters – which affects the continued lives of people. In Moss and lichen, Lawson presents a very well-rounded appreciation of mosses and lichens, people, and the well-being of the planet.

In addition to the biology and ecology, there’s plenty of direct mention of mosses and lichens and people in Moss and lichen.

The whole of Chapter seven – Curious observers: A field trip – is devoted to such luminaries as: William Starling Sullivant (‘Father of American Bryology’); William Borrer (‘Father of British Lichenology’); William Mitten (the bryologist who travelled the world looking at mosses while never leaving Europe); Ellen Hutchins (Ireland’s first female botanist – and proving that you don’t have to be a man, named William, to study cryptogams); and Elke Mackenzie (‘The Unsung Heroine of Lichenology’). There’s also a very good mention of one who is doing important work in the 21^st century; Dr Rebecca Yahr at the Royal Botanic Garden Edinburgh. Holding the title of Lichen Biodiversity Scientist, “she teaches lichen courses for the general public and leads lichen safaris in the gardens, hoping to inspire interest in lichen diversity” (p. 179).

As Yahr does her best to promote lichens, we must also applaud Lawson for what she has done in Moss and lichen – to give a major boost to moss [and lichen] appreciation. In doing so, she is doing her bit to counter the scourge and unwanted arrogance that has been called “vascular plant chauvinism” (Kathrin Rousk & Juan Carlos Villarreal A, 2025). Well done – to both author Lawson and publisher Reaktion Books – for taking such a stand!

The more artistic dimension of plants and people is covered in Chapter six Literary ecology. Despite starting with a bit of a ‘spoiler’ for literary classic Moby Dick, this chapter cites many instances of moss and/or lichens in literature – which includes poetry, and artwork (with John Ruskin). Accordingly, we have mentions of Robin Wall Kimmerer’s Gathering Moss: A Natural and Cultural History of Mosses; the 1992 special volume of British Bryological Society titled Mosses in English Literature – a collection of almost three hundred quotations … covering 2,000 years of writing; the reminder that “mosses and lichens were associated with death (tombstones) and filth, followed by barrenness and stagnation owing to their presence in waste places, and thence to more abstract associations such as loneliness, solitude, shadows, dreams and haunting” (p. 141), which tradition goes back “Certainly, beginning with Ovid (43 BCE–17/18 CE)” (p. 141); there’s a fascinating discussion about the proverb, ‘a rolling stone gathers no moss’, and its role as a tool for psychological analysis in American Veterans Affairs hospitals, particularly in cases of schizophrenia [featuring a spoiler for the film of Ken Kesey’s One Flew over the Cuckoo’s Nest]; JRR Tolkien gets a mention because he “plays with the proverb at the end of The Return of the King” (p. 143); Beatrix Potter and Justin Bieber are ‘namechecked’; we are told that “Mosses often appear in fairy tales, the best known being ‘Mossycoat’” (p. 147); whilst Lawson – tantalisingly – tells us that “On 6 April 2018 the British Bryological Society tweeted, ‘Anyone tempted to do a haiku with lichens?’” (p. 152), but we don’t get to find out if any such haikus were forthcoming; “British science fiction writer John Wyndham (1903–1969) made use of the link between lichens and longevity in his lively Trouble with Lichen” (p. 153); and “Bill Bryson, a writer who teaches us with humour and wit, includes lichens in his A Short History of Nearly Everything (2003)” (p. 160).

And there’s plenty about the more practical ways in which moss and lichen have been exploited by people in Chapter eight #moss#lichen. Using ‘hashtags’ (Clodagh O’Brien) gives this chapter a very modern look, which seems appropriate because, no matter how ancient a lifeform mosses and lichens are, they continue to be relevant to people and the planet in the 21^st century – and beyond. The role of mosses and lichens in the lives of people is summarised by this chapter’s solid starting  sentence: “Mosses and lichens have supported the growth of human culture in many activities: survival (famine food), brewing, baking, biomonitoring, caulking, decorating, embalming, feeding livestock, diapering, dyeing, healing (materia medica), packing, perfuming, powdering (hair), poisoning, sniffing, snuffing, spiritual/ritual practice, stuffing, tanning and so on” (p. 187).

Lawson then goes on to highlight several plant-people interactions. #medicinalmoss has a big section about the role of sphagnum in World War I. #medicinallichen is a timely reminder of Linnaeus’ role as a doctor of medicine with mention that he “published an influential medical textbook in 1749, in which he included seven lichens: … Usnea spp. for wounds, bleeding and umbilical hernia; … Peltigera canina for hydrophobia (rabies); …; and skull lichens for epilepsy and haemorrhages” (p. 191). The section sub-titled #lichendyes, whilst maybe looking at one of the most familiar uses of lichens, provides lots of material that was new to this reader – e.g. the impressive range of colours that lichen dyes provide, the importance of ‘lichen purple’ to rival that of mollusk [sic.] purple in antiquity, and the notion of ‘salvage botany’ to reduce exploitation of lichens from the wild.

And the section sub-titled #horticulturalmoss&lichen is perhaps best summarised in the words of Lawson, “Many gardeners only belatedly realize the horticultural potential of cryptogams in their gardens – usually they have moved in and made themselves permanent” (p. 201), although “One of the most famous moss garden temples, Saihō-ji, now a World Heritage site, was founded in 731 by Emperor Shomu” (p. 201). In #moss&lichenwildlife, Lawson looks beyond people to the ways in which wildlife – mainly birds, but a bee [moss carder bee] is also mentioned – exploit moss and lichen.

Finally, in #moss&lichenconservation, the author sounds a more downbeat note with: “The stories of rare mosses and lichens, and their disappearance and reappearance, enhance our understanding of the complexities of their biology. In some cases the race is to document species before they disappear; in others, it is to conserve. Bringing moss and lichen into botanic gardens in an intentional way is raising awareness about cryptogams” (p. 211). Easily over-looked – quite literally – and under threat of over-exploitation in the case of dye-bearing lichens, and moss-made materials such as peat [and even under threat from those you’d assume would be keen to look after them: “Sometimes research itself is a danger to a rare moss. The entire known population of the Antarctic endemic moss Schistidium deceptionense has been endangered by trampling as a by-product of research” (p. 211)], mosses and lichens are vulnerable to the actions of people. But, Lawson also indicates that there is hope, in the last few sentences of Moss and lichen: “Mosses and lichens are becoming more visible, recognized for their extraordinary biology and beauty. One remembers the line from Lew Welch’s poem, ‘why am I made to kneel and peer at Tiny?’ Because that’s how we learn to respect mosses and lichens for their many contributions to the well-being of the Earth and its inhabitants” (p. 214). People may be a large part of the problem for those charming cryptogams, but they are also a major part of the solution, too. And that’s a suitably optimistic way to end the book.

Second, and in keeping with my expectation of a strong people dimension, when I look at a book about lichens there are a few names I expect to see mentioned: Simon Schwendener (for his work on the dual nature of lichens (Rosmarie Honegger, 2000; ME Mitchell, 2002), Heinrich Anton de Bary (because of his association with the term ‘symbiosis’ (WB McDougall, 1918)), Beatrix Potter (for her contribution to lichenology, in particular her advocacy for the dual nature of lichens (e.g. here, here, Gary Perlmutter, here, Sahastrarashmi, and Maria Popova), but which support has been questioned), and Toby Spribille (for his part in reporting the three-partner nature of lichens [for more on this see Toby Spribille et al. (2016), and commentary thereupon here].

All four were included in Moss and lichen, three as expected (and with sources), but Lawson was silent on Potter’s lichen work, mentioning only a little moss bed in her book, The tale of Tommy Tiptoes . Pleasingly, reference to de Bary gave Lawson the opportunity to discuss the debate about who first coined the term ‘symbiosis’ (Estelle Sia Yu Qi). Accordingly, and entirely appropriately, there was a name-check for Albert Bernhard Frank in this regard. But, do be aware that de Bary is – somewhat curiously, listed in the Index as ‘Bary, Heinrich Anton de’, and with only one – page 71 – of his several mentions in the text – pages 71, 72, 76, and 77 – indicated.

Knowing much less about mosses than I do lichens I have no such similar expectations regarding named individuals from a book about moss [although I was surprised to see Beatrix Potter mentioned in Moss and lichen in this regard]. I do, however, expect to see a decent mention of sphagnum and maybe use of peat in horticulture. On that score, Elizabeth Lawon did not disappoint: There’s practically a whole chapter – number five Bogland – devoted to the wonders of Sphagnum species and the peaty habitats they create, inhabit, and maintain, and there’s plenty about war-time uses of this medicinal, liquid-absorbing moss in Chapter eight #moss#lichen.

What about the evidence?

Overall, the facts [and they are numerous (which is great)**** – my set of notes for this book is the longest I’ve ever made in reviewing a book] in Moss and lichen seems to be suitably statement-sourced and therefore supported by evidence. Which is always important in a non-fiction book about plants that presents many scientific facts. But, special mention must be made of the book’s Introduction*****.

Although that section is important in supplying context, and scene-setting, for the rest of the book, it does contain many statements of fact for which no sources are indicated in-text (by way of super-scripted numbers that relate to the book’s References section). For example, “A single moss cell isolated from a mother plant and carried by the wind can become a new plant in a new place, a phenomenon known as totipotency” (p. 7); “… while lichen belongs to no kingdom but its own” (p. 8) [this statement was a surprising one – as far as I was aware lichens are included within the Fungal Kingdom, not their own separate one. Unsurprisingly, I was keen to see the source for this fact]; “Although Linnaeus classified lichens as plants, that changed in 1867 when Simon Schwendener revealed the lichen as a dual organism composed of one fungus and one alga” (p. 8) [this issue is addressed by source-cited text in a subsequent chapter]; and “Symbiosis [in the lichen] most likely began in the ocean, as fungi used these fellow organisms as sources of nutrition” (p. 12). When my students did this sort of thing in an introductory paragraph to an essay, I let it go – so long as the facts were returned to – and suitably sourced – later in their assignment. Not having had the inclination to devote the necessary time to check every instance mentioned above elsewhere in Moss and lichen, I can’t be sure whether Lawson did indicate sources for all of those introduced bits of information if and when mentioned in other chapters in the book. So, I will just have to note that – despite over 490 numbered notes regarding sources throughout the whole book – this particular section of Moss and lichen appears to be incompletely evidenced.

Unfortunately, the source-unsupported-statement issue isn’t confined to the Introduction. In several other chapters statements are made that require a source, e.g., “There are only a few aquatic or partially aquatic mosses, and, of the 250 freshwater and 700 marine tidal lichens, most are amphibious” (p. 102); “Mosses and lichens are the dominant photosynthetic cover in both the Arctic and Antarctic” (p. 108); “Nematodes, the most abundant animals on Earth” (p. 114); “Bryologists have settled on saying that there are between 100 and 380 species of sphagnum” (p. 128); “… bogs have stored homely household items such as kegs of butter as well” (p. 136); and “Researchers agree that mosses provide insulation, improve sanitary conditions, maintain humidity, accommodate growing chicks through elasticity, and protect via antimicrobial, antifungal and antiparasitic compounds” (p. 207).

But, those – comparatively few – instances of insufficiency of stated sources notwithstanding, Moss and Lichen remains a commendable piece of scholarship.

Summary

Reaktion Books’ Moss and lichen by Elizabeth Lawson is a most welcome addition to that publisher’s Botanical series. Whilst still delivering that all-important mix of plant-and-people to its subject matter, it boldly extends the series’ reach beyond the seed plants to so-called ‘lower’ plants, and out into the fungal kingdom (and even to the bacterial realm with inclusion of cyanobacteria). Belying the smallness of stature of its subjects, this is a giant of a book delivering biology, ecology, environmental relevance, ethnobotany, uses, and artistic relevance of moss and lichens. I consider Moss and Lichen a ‘must-read’ for everybody who has any interest at all in people and/or plants. Having now broken the mould with Moss and lichen, where next for Reaktion Books’ Botanical series? Will we see titles on ferns, other fungi, and even algae? I do hope so!

* Pine by Laura Mason and Fred Hageneder’s Yew were the only non-angiosperm titles prior to 16^th December 2024.

** Very well(!)

*** Moss and lichen compares very favourably with Lawson’s other title in Reaktion’s Botanical series, Primrose, that I had the pleasure of reviewing [see here].

**** Amongst the facts that I learnt from reading Moss and lichen were: the job of an “apprentice bat maker”; the name for an early microscope; the importance of ‘pub botany’; the notion of ‘nannandry’ in mosses; the forms in which carbohydrates are transferred from the photosynthetic partner to the fungus within a lichen; that mosses and lichens are poikilohydric anhydrobiotes; the existence of vitricolous lichens; the existence of – and differences between – vagrant and erratic lichens; that some lichens can live within rock; the phenomenon of ‘quartz oases’; the presence of ‘mice on ice’; the delightfully contradictory etymology of the word sphagnum; the presence – and role – of retort cells in the stems of mosses; and the role of ‘vortex rings’ in moss spore dispersal.

Undoubtedly, there are more moss and lichen facts than ‘you could shake a stick at’ in Lawson’s amazing book. And, for invaluable insights into ‘how the book came to be’, see the author’s own blog account here.

***** I must here mention the book’s first sentence, that starts the Introduction: “Of all the photosynthetic life forms that clothe the Earth and convert carbon dioxide to oxygen, mosses and lichens have earned first place as pioneers, creators and restorers of habitat” (p. 7). Whilst it’s a very good way to begin the book, it must be pointed out that it gives the rather misleading impression that the oxygen released in photosynthesis comes from CO₂. In reality, the oxygen comes from the water, that is also involved in photosynthesis.

REFERENCES

Rosmarie Honegger, 2000. Simon Schwendener (1829–1919) and the Dual Hypothesis of Lichens. The Bryologist 103(2): 307-313; https://doi.org/10.1639/0007-2745(2000)103%5B0307:SSATDH%5D2.0.CO;2

WB McDougall, 1918. The classification of symbiotic phenomena. The Plant World 21(10): 250-256; https://www.jstor.org/stable/43477691

ME Mitchell, 2002. “Such a strange theory”: Anglophone attitudes to the discovery that lichens are composite organisms, 1871–1890. Huntia 11(2): 193-207.

Kathrin Rousk & Juan Carlos Villarreal A, 2025. Time to end the vascular plant chauvinism. Nat. Plants 11: 3; https://doi.org/10.1038/s41477-024-01876-9

Toby Spribille et al., 2016. Basidiomycete yeasts in the cortex of ascomycete macrolichens. Science 353(6298): 488-492; doi: 10.1126/science.aaf8287