Do we need another picture book about plants?

Rare plants: The story of 40 of the world’s most unusual and endangered plants by Ed Ikin, 2020. Welbeck Publishing Group, in association with RBG Kew.

If you’re looking for a longer read of a botanical nature for the winter 2021 holiday season (global), or for a break during renewed working from home (UK/local), may I offer you some thoughts on Rare plants by Ed Ikin [which book is here critically appraised]?

Some general comments about the book

It’s entitled Rare plants, but is that enough to entice the would-be reader to open it and read within? Hopefully, the sub-title – The story of 40 of the world’s most unusual and endangered plants – gives a little more idea of the book’s subject matter. The plants chosen are arguably both unusual and endangered, which makes them not only rare, but also precious. And the way in which the material is packed is an interesting marriage of text and an “evocative blend of artwork sourced from the Kew archives and authoritative and illuminating art” [from the book’s back cover].

The 40 plants [see how many I’ve managed to mention in this article…] are presented in alphabetic order, by scientific name. There are approx. 205 pages of main text, each separate plant entry is either 6 (e.g. baobab, mandrinette, snake’s head fritillary, smooth purple coneflower…), or 4 (e.g. suicidal palm, egg-in-a-nest orchid, thermal water lily, sofar iris…) pages long. The book is completed by a Glossary, suggestions for General Reading, and six 4-columned pages of Index. Rare plants is generally very well written with some nice touches of style and phrasing.

Apart from the single page of Introduction, every main text page appears to have at least one image on it. This super-abundance of illustrations – which include paintings of plants, landscapes, copies of letters, herbarium sheets, pages from books and journals, and a single photograph – means that the ratio of text: pictures for each plant entry is quite low, e.g. of the 6-page entry for Opuntia only approx. 1.5 pages are text; the 6 pages about the Chilean wine palm has <1.5 pages of text. Whilst that may have meant that writing the book was an easier task than its 200 plus pages might suggest, one can only imagine that any time saved there must have been more than used up selecting the hundreds of images that embellish – and brighten-up – this book.

The book is pleasingly wide-ranging. Topics covered include: ethnobotany, plant taxonomy, plants-and-people, endangered plants, conservation, and the important role of botanic gardens. Threats to plants include: habitat destruction, over-exploitation of the plant resource, climate change (which is even more dramatically called ‘climate breakdown’ on p. 9), and represent quite a depressing catalogue of the ways in which plants have been reduced in number – i.e. become rare – over time. But, the roles of in-situ and ex-situ conservation, partnerships between botanic gardens and local peoples, and the need to encourage more sustainable management/harvesting practices, are all mentioned where appropriate within the plant stories and give some hope that all may not yet be lost, for at least some of the plants concerned.

How were the plants chosen?

Apart from their presumed rarity, nowhere in the book are the criteria for selection of the included plants stated. That omission gives me permission to suggest that the 40 entries are a curious mix that includes: Aloe vera (which, Ikin tells us, is no longer found in the wild, so is probably more extinct than rare?); mistletoe; common ash (if it’s ‘common’ why is it in book about rare plants? Its inclusion here makes the important point that what was once common may now no longer be so. The once previously-widespread ash is under such serious threat with the rapid onset of ash dieback from the mid-2010s that its status is now considered ‘near threatened’ per the IUCN’s red list); tangle weed kelp (Laminaria hyperborea, one of two non-seed plant entries, but, as a brown alga, is it really a ‘plant’ and therefore a legitimate subject for Rare plants?); African violet (Streptocarpus ionanthus, which – I was surprised to learn – is no longer in the genus Saintpaulia)*; highland coffee (for those who knew that tea was grown in Scotland, this is not a reference to coffee grown in the Scottish highlands, but to the high lands of countries in West Africa where the plant is indigenous); the genus Eucalyptus (with hundreds of species in the genus, this increases the number of plants considered in the book by at least a factor of 10(!)); Attenborough’s pitcher plant; enset (Ensete ventricosum, a relative of the banana that’s a staple food for approx. 20 million Ethiopians (James S Borrell et al., Annals of Botany 123: 747–766, 2019; https://doi.org/10.1093/aob/mcy214). However, as “an abundant component of sub-Saharan forests, and classified as of “Least Concern” in IUCN’s Red List because of its stable population” (p. 73), it is not clear to me how it qualifies as one of Ikin’s rare plants); Tunbridge filmy fern (the 2^nd non-seed plant entry); not one, but two water-lilies – Nuphar pumila, and Nymphaea thermarum (Rebecca Povilus et al., PNAS 117: 8649-8656, 2020; https://doi.org/10.1073/pnas.1922873117) (the latter of which pair, although only ‘discovered’ in 1987, is already ‘extinct in the wild’ – a victim of human over-exploitation of its habitat); crested cow wheat; London plane; and snake’s head fritillary.

On whose authority?

Somewhat surprisingly – given the book’s RBG Kew co-publication pedigree and the author’s post as Director of Wakehurst** (home of the Millennium Seed Bank), authorities are not shown with the scientific names, neither at the head of the plant entries, nor within the text. This seems rather at odds with Ikin’s text which emphasises the importance of naming plants correctly so it is crystal clear what taxon is intended (e.g. p. 29 re Chatham Island Christmas tree). Such nomenclatural clarity is greatly assisted by using the plant’s full binomial scientific name with the relevant Authority. The book’s opportunity to set an example in that regard has been missed.

Getting to grips with the jargon

For a tome that looks rather art-heavy, and therefore might appeal to a particular demographic, the text may appear a little too technical and ‘sciencey’ in places. It’s true that the book deals with serious issues of science, which necessitates use of specialist words and terms, but I interpret that as being part of an unwritten goal of the book of attempting to increase the plant literacy of its readership. Many of the likely-to-be-unfamiliar technical terms are explained in-text or in the book’s two pages of 2-columned Glossary. For example, the term ‘allelopathy’, although mentioned on p. 181, it’s not really explained, but it is defined in the glossary. Curiously, upon its first mention on p. 25 the term ‘Anthropocene’ is not explained, although it is defined in-text on its second mention on p. 144 (and in the glossary). Other terms, such as bioprospecting, and hapaxanthy***, are not only explained in-text, but also defined in the glossary, although using different wording in each place, which can be defended as a useful pedagogic tactic of recap and reinforcement to enhance understanding. However, the very specific term ‘meta–population’ is neither explained in the text, nor included in the glossary.

For some other terms, whilst being explained in-text, the definitions seem a little unusual. For example, is “the degree to which its watery habitat moves” (p. 153) the most appropriate definition of ‘turbidity’, a reference to one of the environmental preferences for Nuphar pumila. And, is ‘monocellular’ (p. 115) really the correct word to describe the frond of Hymenophyllum tunbrigense, a sheet-like structure that’s one-cell thick? Surely, the preferred term should be the more-widely-used word ‘uniseriate’? In my mind, monocellular conjures up an image of an entity that consists solely of a single cell. As it does for writers of easily-found definitions on the internet [although in fairness, I should say that Lexico also defines it as “Consisting of or involving single cells; (of a layer) one cell deep”, and Merriam-Webster says it’s a medical term meaning “having or involving a single kind of cell”]. And, the accuracy of the glossary definition of ‘lignin’ – as “a hard woody tissue [my emphasis] found in trees and shrubs” (p. 217) – must be challenged. As should the glossary definition of photosynthesis, “the biochemical process plants uses [sic.] to make sugars from sunlight and carbon dioxide, which are then converted to energy” (p. 217).

A comment about the illustrations

Although pictures of the plants are always welcome (and there’s a load of them in Rare plants), the value of some of the reproductions of hand-written letters from centuries, or even decades, ago is questionable because many of them are so hard to read (e.g. pages 26, 63, 70, 76…). Even though the letters’ contents are generally summarised in the book, it might have been more useful for a ‘translation’ to have been provided for each such document. However, and as they are, they still have some worth, not only for a glimpse of the beautiful craft of penmanship that some of them display, but also in giving us a person dimension to the plant side of things.

Some comments about the prints

Rare plants is that rare thing, a plant book in a box, which also contains a collection of prints that could be used to adorn walls and add a bit of botanical beauty to your home, office, etc. But, although promoted as containing “40 frameable prints”, purchasers might be a little disappointed to discover that there are only 20 pieces of card, each of which is printed on both sides. So, you couldn’t actually display 40 framed prints at the same time, you’d have to choose which of each pair to have on view. However, the majority of those prints are superb works of botanical art, and, at almost A4 size, are big enough to display as they are. Apart from the print of the majestic baobab Adansonia grandididieri (which is a copy of a black-and-white photograph taken in 1882****), all the other 39 prints are from multi-coloured paintings – whose details of subject, artist, and source are part of the legend to the same illustration in the main book’s text.

Curiously, the prints are not always of the plant that is ‘name-checked’ in the main collection. For example,  an unspecified Gracilaria, a beautiful marine red alga, is shown as a print, but is not one of the book’s 40 named rare plants. The named plant whose entry the red alga picture illustrates is tangle weed kelp (Laminaria hyperborea). Why there is no print of the kelp is not stated. And, unless we are told that only kelp that illustrates the entry, Laminaria cloustoni, is regarded as a synonym for L. hyperborea, we’d have been left with the impression that the named plant wasn’t even illustrated in-text*****. A similar situation exists where Hibiscus trilobus is the print, but the main entry taxon is Hibiscus fragilis. And for the 4-species plate of irises, none of which is the main entry plant, Iris sofarana.

Even more unsatisfactory is the case of Hymenophyllum tunbrigense. Despite being one of Ikin’s named 40 rare plants, it is not shown as a print and isn’t illustrated at all in the main book entry. Instead, all of the picture honours go to the related Hymenophyllum speciosum. Is Hymenophyllum tunbrigense so rare that nobody has been able to find it to paint it? Or has it never been thought sufficiently worthy of being painted? It’s certainly been photographed, e.g. here, here, and here.

A comment about sources

There are no in-text references. Yes, there is a General Reading list at the end of the book. But, and apart from “Curtis’s Botanical magazine, continuously published since 1878” (p. 218), that seems to just include books (of which three of the 21 are about Marianne North, Victorian botanical artist of note). Although, at best, these books are secondary sources for information presented in the book, it would be a mammoth task to relate individual books to specific facts in the text. The IUCN red list – which is referred to many times throughout the book (e.g. IUCN has 26 entries in the Index), and is clearly a work of some importance – is not mentioned.

I must therefore ask: Is the plant story in the book? To which my answer must be, ‘sort of’. Ikin makes statements and you get glimpses of the tales about each plant, but that’s as far as it goes. To get more information on each plant – or just to check the veracity of what Ikin says – you have to do quite a lot of fact-finding on your own. That can either be frustrating – for those of us who appreciate properly-evidence-based plant books, or it can be part of the joy of such a book, because its sets a challenge for the reader to search the interweb or whatever to get the facts behind the tantalising snippets presented in the text.

Rare plants is a really good book. It’s such a shame about its scarcity of sources.

40 plants, 40 different stories…

Each plant has its own story to tell, and Ikin uses those to develop different aspects of the book’s message, which can be summarised as ‘all plants are precious and losing any would be a bad thing’. Another important message, which is more of a plea, is that “for plants whose usefulness is just being discovered, conservation needs to be a central outcome of any commercial interest” (p. 107). That such a comment is needed is clear from several of the plant examples in the book, whose usefulness to people has led to their demise or reductions in numbers. [Ed. – But, it’s often just as bad for plants that aren’t deemed useful, they become categorised as ‘weeds’, demonised, and destroyed…]. So, time for a little message/reminder from me: ALL plants are useful.

If I had to select one plant to highlight the concerns that Ikin strives to put across in Rare plants, I’d choose Coffea stenophylla (highland coffee). Summarising what Ikin tells us about this plant, we are reminded that globally, production, consumption, and sales of coffee are extremely big business, and most of that trade concerns arabica coffee from Coffea arabica. Unfortunately, the arabica coffee plant is quite delicate and threatened in several ways, not least of which is its inability to cope with demands from a warming climate. In the search for more resilience amongst the coffee crop, the highland coffee plant (which is indigenous to Guinea, Sierra Leone and Côte d’Ivoire in West Africa) is being investigated, either as a cultivated crop in its own right (coffee made from the plant is apparently delicious and arguably superior to arabica), or once interbred with other Coffea species. The problem with both of these approaches is the rarity of C. stenophylla in the wild. Although eventually found in several locations in Sierra Leone, wild stands of highland coffee were isolated and fragmented as a result of forest clearance for agriculture or timber. The current IUCN red list status for this species is ‘Vulnerable’, with a downward population trend. Ikin concludes that plant’s entry by reminding us of the need to conserve the world’s plant diversity if we are to exploit all the resources available to us to help cope with threats to food – and drink – security such as climate change.

What Ikin didn’t say about this plant – arguably because at least some of the following information wasn’t available when the book was finalised prior to its 2020 publication date – was this. Although no longer being farmed nowadays, more than 100 years ago C. stenophylla was widely exploited as a coffee crop species across Upper West Africa and further afield (Aaron P Davis et al., Front. Plant Sci., 19 May 2020; https://doi.org/10.3389/fpls.2020.00616). Just because a crop is no longer farmed doesn’t necessarily mean it has no further value. Indeed, Davies et al. (2020) conclude that “C. stenophylla may possess useful traits for coffee crop plant development, including taste differentiation, disease resistance, and climate resilience”. Furthermore, Aaron P Davis et al. (Nat. Plants 7: 413–418, 2021; https://doi.org/10.1038/s41477-021-00891-4) went on to confirm historical reports of highland coffee’s superior flavour and “uniquely, and remarkably, reveal a sensory profile analogous to high-quality Arabica coffee”. They also report that C. stenophylla can grow at “a mean annual temperature 6.2–6.8 °C higher than Arabica coffee”, which therefore “substantially broadens the climate envelope for high-quality coffee and could provide an important resource for the development of climate-resilient coffee crop plants”. This additional data not only strengthen Ikin’s plea for conserving plant diversity, but also underline the relevance of Coffea stenophylla as an entry in Rare plants.

A reviewer’s little indulgence

Do I have a ‘favourite’ rare plant from the book? Yes, and it can only be Opuntia chaffeyi (Elton Roberts, Alan Hill) – even though it’s not technically one of the book’s ’named 40’ because the entry under which it is discussed is for the genus Opuntia. Sadly, the specific epithet is not named for me, but honours another botanist, Dr Ellswood Chaffey. According to Ikin, the cactus is nowadays “limited to one dried-up Mexican lake” (p. 161). Listed in the IUCN Red List as critically-endangered (one category above ‘extinct in the wild’ (which itself is just above extinct…)), Ikin tells us there are “only 15 known mature specimens” (p. 162) (presumably in the wild), which makes it a very rare plant indeed and justifies its inclusion in Rare plants.

Every question needs an answer

To return to the question posed in this blog item’s title, do we need another picture book about plants? The rational me says: Probably not. The maybe-irrational, plant-lover part of me says: There’s always room for one more, you can never have too many plant books in your life. And, if you can’t visit the places that house the real thing or look through the archived plant portraits, etc. hidden in the depths of Kew’s vaults, then a book such as Rare plants is a very good substitute.

But, and importantly, Ed Ikin’s tome isn’t just a book of plant pictures. It marries plant portraits with serious text that enumerates the very real threats plants face and which have caused many of them to become rare. Perhaps by seeing the beauty of the 40 rare plants in the book’s illustrations and prints we might better appreciate what we are in danger of losing – or have already lost in the wild in some cases – and that can only help raise public awareness of the dangers facing plants on a daily basis. If botany needs something as graphic and iconic as the giant panda munching bamboo or the polar bear atop a shrinking piece of ice to front the campaign to protect our planet’s flora, then there are 40 in Ed Ikin’s Rare plants to choose from. But, how about Lotus maculatus,

“a critically endangered endemic of Tenerife in the Canary Islands” (Nicholas Hind, Curtis’s Botanical Magazine 25(2):146–157, 2008; doi:10.1111/j.1467-8748.2008.00613.x), as the plant equivalent of the ‘poster boy’ to front the ‘protect the planet’s plants’ campaign?

Summary

Rare plants by Ed Ikin is a serious and thoughtful book that is a very worthwhile read. With its ‘coffee table book’ quality illustrations, it’s also a beautiful book just to leaf through. Whatever reason you might have for picking it up, it is highly recommended to all who love plants. Don’t what to take my word for it? You don’t need to, Rare plants is ‘officially’ recognised as “a work that makes a significant contribution to the literature of botany or horticulture” by its having won (jointly with multi-award-winning Merlin Sheldrake’s Entangled Life) The CBHL [Council on Botanical and Horticultural Libraries] 2021 Annual Literature Award.

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* Ikin states that the plants were “discovered at the end of the nineteenth century” (p. 186) by Baron [but Indexed as Barom…] Walter von Saint Paul-Illaire (commemorated in the name of the genus to which the plant was originally assigned), a colonial governor of Tanganyika, which at that time was part of the German colony of German East Africa. This sort of statement seems questionable since it’s highly likely that the plant had already been ‘discovered’ – and long before an administrator for the occupying European colonial power chanced upon it – by the original inhabitants of the area. It’s possible that use of the word ‘discovered’ here may indicate that this event was the start of the formal process of assigning the plant a proper scientific name. That may be so. And in which case, that needs to be made explicit. Otherwise, use of such phrasing risks perpetuating concerns about who actually discovered a particular plant. This is of concern for at least two reasons. First, because it is highly relevant to the present day conversation about ‘decolonising botany’ (e.g. Maura Flannery, here, Alexandra Yellop, Tomaz Mastnak et al. (Environment and Planning D: Society and Space 32: 363 – 380, 2014; doi:10.1068/d13006p), and in this article by Alexandre Antonelli, Director of Science at the Royal Botanic Gardens, Kew). And second, as it relates to claims regarding intellectual property rights of traditional plant knowledge if such plants are exploited (e.g. Marianne Lotz (Business & Professional Ethics Journal 21(3/4): 71–94, 2002; http://www.jstor.org/stable/27801290), Ian Vincent McGonigle (Journal of Law and the Biosciences 3: 217–226, 2016; https://doi.org/10.1093/jlb/lsw003), Letitia M. McCune (Ethnobiology Letters 9(1): 67-75, 2018; doi: 10.14237/ebl.9.1.2018.1076), and Michael Heinrich & AlanHesketh (Phytomedicine 53: 332-343, 2019; https://doi.org/10.1016/j.phymed.2018.04.061)).

** Since the book’s publication, author Ikin has been elevated from being Wakehurst’s Deputy Director to Director at Kew’s Sussex-situated sister site, Wakehurst (which I was surprised to learn is owned by the UK’s National Trust, and only managed by Kew). This notable advancement in employment status is surely evidence that writing about plants can boost one’s career. Never underestimate the positive promotional power of phytology.

*** The term hapaxanthy was new to me. A quick bit of research – looking it up in the Illustrated plant glossary – tells me that hapaxanthy means more or less the same as the more-familiar term monocarpy, but is applied most commonly to describe that ‘seed-once-then-die’ property of bamboos and palms. Appropriately, in Rare plants it appears in the entry for the suicide palm (Tahina spectabilis (John Dransfield et al., Botanical Journal of the Linnean Society 156: 79–91, 2008; https://doi.org/10.1111/j.1095-8339.2007.00742.x)). Curiously, as a “palm tree of imposing dimensions” (p. 193), the plant was only ‘discovered’ in 2005/2006 in Madagascar. [Ed. – hapaxanthy is also synonymous with the term ‘semelparous’].

**** For more – and more-recent – photographs of baobabs, see here.

***** A very good example of a plant you’d probably not realise is rare is the tangle weed kelp, because it’s a marine macroalga that grows usually totally submerged and is only uncovered (and then only partially) at extremely low tides. Yet, rare it apparently is – at least around parts of the coast of the UK where we are told “over 95 pee cent of the kelp forests of Sussex, UK, have been lost” (p. 134). That pretty damning ‘statistic’ is eminently quotable when discussing decline in ‘plants’, which makes it all the more irritating that its source is not stated in the book. [Ed. – published sources that make this claim can be found here, here, here, here, and in the report by Saul Mallinson with support from Chris Yesson].