Botany – but not just for gardeners!

A Gardener’s Guide to Botany: The biology behind the plants you love, how they grow, and what they need by Scott Zona, 2023. Cool Springs Press (an imprint of The Quarto Group).

Like many plant-interested regular users of Twitter I have some familiarity with Dr Scott Zona and his attempts at improving botanical literacy amongst the Twitterati with his beautifully illustrated examples of various botanical terms and phenomena. It was therefore a nice surprise to discover that he has written a book on plant biology, A Gardener’s Guide to Botany [which tome is here appraised]. There’s a lot I want to say about this book. So buckle-up for a long read.

TLDR: A Gardener’s Guide to Botany has the potential to be a truly great plant biology book. Fix the Index, add sources, provide scale bars where needed, tidy-up inconsistencies in the text (and maybe add a glossary…), and Zona’s book will be a terrific resource.

Fairly objective description of the book

The book’s approx. 230 pages of main text is spread over 8 chapters, entitled: Being a plant; Plant parts and what they do; What a plant needs: Water; What a plant needs: Light; What a plant needs: Nutrients; Defense [US spellings throughout…]; Reproduction; and Seed dispersal. The first two chapters set the scene and give a good account of basic plant biology. The next three examine the plant’s relationship to three of the most important non-biological factors that are essential to a plant’s survival. The final trio consider how the established plant survives the attention of those organisms that would harm it, so it can produce the next generation, and send it on its way to become a separate plant. The book concludes with: Further reading; About the author (a short ‘biog’ of Dr Zona); Acknowledgements; Photo credits (but nothing about the illustrations?); and an Index.

Further reading is almost three pages of items – arranged by named chapter – and includes books and scientific articles. Of the 46 items listed, 18 are dated post-2015, which indicates a pretty up-to-date book. Most – c. 89% – of the really recent items are scientific articles which indicates the author’s commitment to providing suitably primary-sourced material. There appear to be very few explicit indications in-text relating material to sources stated in the further reading listing. For more on the index, see The index section below.

A Gardener’s Guide to Botany provides a beautifully and abundantly illustrated, pretty full account of plant biology and ecology (that’s not mired in the molecular minutiae that can be a feature of many modern-day botanical textbooks).

A more subjective assessment of the book

General

Text

Zona has a great enthusiasm for plants and their biology, and writes in an engaging way – even if this means sacrificing some scientific objectivity to get a particular message across. For example, he gives a great definition of a tree [in the first of the ‘shaded boxes’, occasional items scattered throughout the book that usually contain fascinating insights into plant biology]: “You can stand in the shade under a tree; you can’t stand under a shrub” (p. 10). He also conjures up images of plant behaviour or research with memorable phrases. For instance, his “Tender, juicy green leaves are the botanical equivalents of a Rolex watch or Chanel handbag.* They are much admired, but they can attract the attention of predators” (p. 141) is understandable, and sets the scene for the chapter on defence that follows. And the idea that “Nitrogen-fixing grasses are the Holy Grail of agronomic research” (p. 140) conveys the importance of this piece of nutrient acquisition and the attempts to introduce this ability into non-nitrogen-fixing crops. However, more questionable is “They are not in the business of pimping for flowers” (p. 195) in connection with biotic pollination vectors.

With an easy-to-read style [although some sections can be quite technical], humour, memorable phrasing, and good links between chapters (and between sections within a chapter), A Gardener’s Guide to Botany is very well-written.

Illustrations

A Gardener’s Guide to Botany is abundantly illustrated, not just with numerous, excellent photographs, but also with beautiful drawings throughout the book – especially at the beginning of chapters. But, who is the artist? I couldn’t find that noted anywhere. Whilst the drawings are generally excellent, the outlines of xylem cells in the diagrammatic cross-section [although this is not stated] of a dicot [although that’s also not stated in the legend] root on p. 46 are very rough and don’t greatly reflect the true nature of those cells’ profiles. Plus, what is the ‘matrix’ that the xylem cells appear to be embedded in? Helpful to readers would be the inclusion of scale bars for the microscopic features that are included in the book – cross-sections of maize leaf, Acorus calamus root, maize stem, and American linden stem, and the views of moss leaf chloroplasts, and an unidentified plant’s epidermal cells.

The plant science

As far as I can tell, the botany in the book is generally extremely good – as one would expect from an expert commentator such as Zona. However, I have to take exception to this statement: “The cells of the secondary xylem are called vessel elements, …” (p. 50). Certainly, vessel elements are a cell type that one can find in secondary xylem, but there are others: “Secondary xylem is composed of tracheary elements, rays, fibres, and interspersed axial parenchyma cells” (Dennis Stevenson); “Xylem consists of four cell types: a) vessel elements and b) tracheids are the sieve conducting cells or tracheary elements, c) parenchyma cells work as storing and intercommunication cells, and d) sclerenchyma and sclereids as supporting cells”; and “Secondary xylem (wood) is a much more complex tissue than primary xylem and consists of a number of different cell types arranged in specific ways. Wood includes an axial system, which moves water and minerals up the stem, and a ray system, which runs horizontally through the stem, that is, in a radial direction” (p. 214) (Thomas Taylor et al., Paleobotany: The Biology and Evolution of Fossil Plants, 2e, 2009). It is therefore not appropriate to state that vessel elements are synonymous with secondary xylem. A revised version of the book – there surely must be one because this tome has an awful lot of great material to offer – can remedy this matter easily by inserting the phrase ‘water-conducting’ between ‘The’ and ‘cells’.

Internal inconsistency

Although generally, and overall, the book has clear messages, there were a few instances of contradictory or confusing statements. For example, we are clearly told on p. 35 that “Plants have modular construction”. Fair enough, and presumably that applies to all plant parts. But, probably not, because on p. 39 we have, “unlike the above ground parts of the plant, which are modular in construction …, roots…”. OK, so roots don’t have modular construction?. On p. 36, we are told “If the internode creeps along the surface of the soil or underground, we get a plant with a horizontal stem (called a rhizome)”. Clear enough, a rhizome is a horizontal stem that grows either above or below the ground. But, on page 53 we are advised that horizontal, above-ground stems are called stolons, and below-ground stems are called rhizomes. The statement on p. 36 is incorrect, the information on p. 53 is correct. Finally, there is a nice, straightforward statement that “The functions of roots are twofold” (p. 40) –support and anchorage, and absorption of water and nutrients. Fair enough [although I can think of at least three functions…]. However, we are subsequently told that: “The production of other roots is a third function of roots”. Oh, so not two but three root functions. But that is almost immediately brought into question by this: “Beyond anchorage and support, absorption, and the production of new roots and shoots, other functions have been co-opted by roots.” Which catalogue of functions continues to grow until, on p. 46, we are advised: “Finally, roots have a function that is just now beginning to be appreciated for its near-universal presence in the Plant Kingdom, and that is, roots house symbionts that are important in plant growth and survival”. I’m happy in the knowledge that there are several functions that roots perform. I just think it would avoid confusion if that was stated right at the beginning, rather than telling us that there are two, and then adding to that count in a teasing way. There is a similar issue with functions of stems…

Technical terms

In keeping with the author’s fondness for scientific phrasing [his Tweets revel in demystifying them for the general public], Zona does not shy away from using technical terms throughout the book – which is good to see. However, their use is a little inconsistent, and in some places where I’d expect to see the proper name of a structure or phenomenon used, it wasn’t. Here are three examples of their non-use. We are memorably told that “Tank bromeliads are inside-out aquatic plants” (p. 87), but I was surprised not to see those tanks given their proper name of phytotelmata. The phenomenon of eutrophication was described on p. 128, but not mentioned by name. And the term phytoliths was not used when talking about silica bodies (p. 153) (Regan Dunn; Matthew Mason).

Chapter 1 Being a plant

The book’s stated purpose is to be “your guide to how plants live, how they are put together, and how they work. It’s about how plants grow, not how to grow plants” (p. 9). Although it’s good to have this clearly stated for the record, it may disappoint many gardening readers who were expecting more – albeit science-backed – information about how to grow plants? However, the book’s sub-title The biology behind the plants you love, how they grow, and what they need, is probably a pretty good indication that it’s not a grower’s guide to plants.** This chapter also tells you what to expect in Chaps 2-8. In terms of the organisms whose botany the book covers, “Plants are a diverse group, including everything from single-celled green alga to enormous, long-lived trees, but they don’t include brown algae (like giant kelp and Sargassum seaweed), mushrooms, or lichens” (p. 23). In an attempt to make more manageable that diversity, Zona recognises four kinds of plants: terrestrial, aquatic [with three sub-categories], epiphytes, and parasites (p. 12). Although he does provide data on numbers of species amongst the major groups of extant embryophyte plant groups on p. 17 – e.g. 300,000+ for angiosperms (which includes 70,000 monocots) – it’s not obvious from the chapter’s four items of listed further reading where they come from. It would be really nice to have sources for such information.

Chap. 2 Functions of plant parts

Generally, this is a very good chapter that considers the functions of roots, stems, leaves, flowers, and fruits, i.e. what these plant parts ‘do’. But, it can be quite technical in places, for example, its opening sentence is: “Plants have modular construction. Unlike animals, plants are built out of repeating modular units…” (p.35). Although Zona likens those units to “identical pieces in a LEGO set” (p. 35), the start of this section is a quite detailed consideration of phytomers, axillary buds, nodes, internodes, leaf arrangement, and axillary buds. For all of these technical terms [and those in other chapters] – which are usually emboldened and explained in-text (p. 35) – it would have been useful to have included a Glossary in the book. That would be especially useful since those terms will be very hard to find in-text using the book’s Index.

Having included green algae (but not brown algae) as plants (on p. 23), the statement that “Photosynthesis is the number-one process for fixing carbon, and the process is overwhelmingly located in leaves” (p. 57), rather overlooks the very important contribution of leafless phytoplankton (Christopher Adams; Patricia Glibert) to that process – certainly in regard to its oxygen production [more here, here, and from Sarah Witman].

For a chapter that includes a wealth of basic plant biology, it’s surprising to note that there are only two items of further reading. Both are books, The Kew Plant Glossary (2^nd edition) by Henk Beentjee, and the 2008 edition of Adrian Bell’s Plant form: An illustrated guide. Whilst neither title can be considered primary sources for the information provided in the chapter, they do fulfil the criteria as further reading. Nevertheless, many more [primary ideally] sources are needed for statements of fact made here [which comment also applies to other chapters].

Chap. 3 Water

Although purists may wince at Zona’s description of osmosis, it serves its purpose, for his intended general audience, and with humour and some neat phrasing. The Cohesion-Tension Theory of water transport is named and described. There is a quite masterful explanation of boundary layer on leaves (which includes fan blades and windscreens of cars). Zona makes an important point about aquatic plants and constraints upon photosynthesis by the slow rate of diffusion of gaseous CO₂ in water. In such plants it is overcome by their additional use of dissolved hydrogen carbonate [though Zona uses the ‘old-fashioned’ term of bicarbonate] ions. Three ‘shaded boxes’ provide information on topics as diverse as Gagliano et al’s work on ‘plants’ ability to hear water’ [although the authors’ names are not included in-text], Vogel & Müller-Doblies’ account of dew-capturing ‘curly-whirlies’, and un-named work [although by Limm et al.] on foliar absorption of water. All three introduce fascinating aspects of plants biology – which probably aren’t that relevant to gardening, but which add value to the book as a plant biology text – and are backed-up by sources in the further reading section [if you do a little detective work for the anonymous items and identify the reference].

Chap. 4 Light

This is quite a technical section – which is why A Gardener’s Guide to Botany makes a very good textbook – and absorption spectra of photosynthetic pigments are covered, as are light-dependent and -independent reactions, C4 photosynthesis, CAM, photorespiration, and why the leaves of forest floor plants have red undersides. Zona even considers why plants don’t absorb green light, and partially debunks the ‘myth’ about the function of the windows of ‘living stones’. The 4-page colour section on variegation includes consideration of the reasons why chlorophyll-free areas may exist and persist. In addition to photosynthesis, this chapter also looks at light-sensing pigments, phytochrome, cryptochrome, and phytotropin. But, and somewhat curiously, there is no mention of the role of a photoreceptor in connection with stomatal opening.

Chap. 5 Nutrients

This contains a great explanatory graphic using a barrel for Liebig’s Law of the Minimum, which was new to me [but would have a been a nice thing to have known about when I was teaching plant nutrition]. And also introduces us to a rather bizarre mnemonic for the 16 essential plant nutrients, whose bizarreness [which Zona acknowledges] is a legacy of the days when iron was considered to be a macronutrient [which revelation was new to me]. But, let’s rewind to the notion of 16 essential plant nutrients. I have always taught my students that there were 17. The difference is that Zona excludes nickel. I find that surprising because nickel is clearly shown as an essential micronutrient in Table 29-1 (p. 685) in my International Edition copy of Ray Evert & Susan Eichhorn’s Raven biology of plants, 8^th Ed, 2013, which book is listed among the Further Reading in Zona’s book. For more on the essentiality of nickel to plants, see David Eskew et al. (Science 222: 621-623, 1983; doi: 10.1126/science.222.4624.62); Patrick Ross et al. (Plant Physiol. 85(3): 801–803, 1987; doi: 10.1104/pp.85.3.801); Guodong Lui et al.; Caio Fabiano et al. (2015) (Front. Plant Sci. 6:754; doi: 10.3389/fpls.2015.00754); Wesley Chun; and Biocyclopedia.

It’s good to see cation exchange capacity mentioned by name, but it was surprising to note that it was only mentioned in connection with clay particles. The negative charges on the surface of humus and organic matter (Richard Stehouwer) are as important as those on clay in this context. Absence of inclusion of organic matter here is particularly odd since elsewhere in the book, Zona is very keen to promote the importance of organic matter in soils, and is a great advocate for organic matter as the gardener’s best friend, and as the basis of the ‘Brown food web’.

There is a good summary account of the role of macronutrients (other than carbon, hydrogen or oxygen), but very little detail [just a half page] regarding micronutrients. A mention of European and American imperialization and guano is a rather interesting aside to the biology in this chapter. The notion of protocarnivory (Mark Chase et al., Botanical Journal of the Linnean Society 161: 329–356, 2009; https://doi.org/10.1111/j.1095-8339.2009.01014.x; Hattie Roberts et al., Sci Rep 8, 10120 (2018); https://doi.org/10.1038/s41598-018-28564-x) is also introduced, as is the concept of litter-trapping plants – another of those intriguing ‘shaded box’ topics – and for which there is a reference in further reading.

Plants and fungal partnerships are covered – as are bacterial partnerships. Although there is no mention of the wood-wide web (Josh Gabbatis; Katie Field & Emily Magkourilou) in connection with fungi, the concept is alluded to: “Scientists are only now beginning to understand how mycorrhizae shuttle nutrients among their partner plants” (p. 138). Although nitrogen-fixing bacterial symbioses are covered, I was a little surprised  not to see at least a mention of the Haber–Bosch process for industrial manufacture of ammonia (Amanda Briney). The role(s) of endophytic bacteria are hinted at. A curious situation relates to van Deynze et al’s 2018 study on nitrogen-fixation by maize: This article is listed in further reading, but the work does not appear to be mentioned in-text.

Chap. 6 Defense

This chapter considers the range of defences – both external and internal – that plants have to resist attack. This is necessary because – and is so nicely summed up by the quote attributed to Kermit the Frog that Zona uses – “It’s not easy being green” (p. 145). Whilst the notion of extrafloral nectaries on bracken fern takes a bit of getting used to [and is surely a case where a more appropriate name is needed for these structures in plants that don’t have flowers?], it was interesting to see the myth that hydrogen cyanide smells of almonds debunked, and who could not like the idea of Liebig’s ‘Law of Soap’? Zona gives us a very good section on airborne defences involving methyl jasmonate and methyl salicylate. With his statement that: “There is some evidence that ectomycorrhiza can transmit messages between conifer species” (p. 172), he is again clearly alluding to the so-called ‘wood-wide web’, but doesn’t mention it by either that name or the less semantically-loaded term of common mycorrhizal networks [CMNs] (Justine Karst et al., Nat Ecol Evol (2023); https://doi.org/10.1038/s41559-023-01986-1).

Chap. 7 Reproduction

This is a great chapter looking at reproduction, although I was a little surprised to see that the abiotic agents of pollination section was almost exclusively devoted to wind – water was only mentioned in passing. Still, there was plenty of interest regarding anemophily [although, bizarrely, this term doesn’t appear to have been used by Zona in the book – per my search of a pdf copy of the title]. There was a fascinating insight into Karl Nicklas’ work on pollen and cones, using wind tunnels and high-speed cameras [which work appears to be covered in an item listed in further reading].

Although it’s nice to see topical relevance and reference used to make particular botanical points, sometimes they don’t work well beyond the USA. Take for example Zona’s comment – in connection with fat-burning thermogenesis of Thaumatophyllum bipinnatifidum – “Jenny Craig, take note” (p. 201). That piece of advice meant nothing to me. Googling, reveals that Jenny Craig is an American ‘weight-loss guru’, which presumably explains Zona’s exhortation thereto.

Chap. 8 Seed dispersal

Always interested in hearing about biological ‘laws’ and such like, I was particularly taken with Zona’s ‘Goldilocks Rule of Seed Size’. Generally, this chapter is a mix of material that’s quite tough going and other that’s much more easy-reading. I got more than a little bogged down in all the text dealing seed types. I know it’s important, but I always find this information far too technical for my taste, as was the equally erudite consideration of ‘Fruits vs. Seeds’. On the other hand, I really enjoyed the material about dispersal methods, which I found much more interesting. And Zona doesn’t disappoint here with accounts of: barochory, hydrochory, ombrohydrochory (re liverworts) [a term new to me], anemochory, endozoochory, epizoochory, synzoochory [another term that was new to me], myrmechory, autochory, and ballistochory. Related to that, a ’shaded box’ in this chapter considered the role of Pleistocene megafauna and seed dispersal, and mentioned the 1982 paper in Science by Dan Janzen & Paul Martin that develops the concept of ‘evolutionary anachronisms’. However, there was no further mention of the article in further reading. Without full citation details, interested readers might have some difficulty tracking it down. For completeness, the details are: Daniel H. Janzen & Paul S. Martin, Neotropical Anachronisms: The Fruits the Gomphotheres Ate, Science 215(4528): 19-27, 1982; doi: 10.1126/science.215.4528.19.

So much that’s new (to me at least)

A Gardener’s Guide to Botany has been a continual source of delight in introducing me to new things [which is always a good thing to see in a book]. If you can think of the following as teasers to encourage you to read the book – rather than ‘spoilers’, some that particularly caught my eye (with some references to more information about them – because the book doesn’t give them) are:

The existence of a plant with leaves more than 25 m long. Apparently, the leaves of Raphia regalis “can reach a record-breaking 25.11 m (82 ft) long by 3 m (10 ft) wide” (The Nerdy Gardener). However, that leaf is divided into approx. 180 leaflets. The bearer of the “largest un-split leaf in the world”, according to the good people at The Trust for Sustainable Living, is the giant taro, whose leaves can reach two metres in length…

That leaves of Psychotria punctata bear acne-like pustules which are home to bacteria that appear to provide growth regulators to the plant host as rent for its home. For more information, see Florian Schindler et al. (Front. Mol. Biosci. 8:683671; doi: 10.3389/fmolb.2021.683671).

The existence of compounds in the wax of needles of mugo pine that not only absorb UV light (which thereby protect the leaf from UV-damage), but also emit blue-light which can be used in photosynthesis. For more on this phenomenon, see JF Jacobs et al. (Progress in Organic Coatings 58: 166-171, 2007; https://doi.org/10.1016/j.porgcoat.2006.08.023).

The concept of fertilizer burn. More at Jackie Carroll; Brody Hall.

That bat guano is a traditional potassium source for plants. More at Kevin Espiritu; Sarah Keleher; Pawan Kumar Misra et al. (Annals of Plant and Soil Research 21(1): 82 – 86, 2019).

That carnivory evolved “once or twice within the liverworts” (p. 131); the traps of the liverwort Colura zoophaga catch unicellular microbes. The reference to Colura carnivory is presumably Wilhelm Barthlott et al. (Plant biology 2: 93-97, 2000; https://doi.org/10.1055/s-2000-9150). The other liverwort alluded to is likely to be Pleurozia purpurea (Sebastian Hess et al, The Bryologist 108(2): 212-218, 2005; https://doi.org/10.1639/6).

The existence of a new category of mycorrhiza – the arbutoid type – in addition to the four I previously knew about [ectomycorrhizal, and the endomycorrhizal forms of arbuscular, ericoid, and orchid (Marcel G A van der Heijden et al., New Phytologist 205: 1406-1423, 2015; https://doi.org/10.1111/nph.13288), and which types are also mentioned in the book]. [Although, as a result of my researches on this matter, I now realise there are – probably at least – seven types of mycorrhiza (David Moore’s World of Fungi).]

Bodyguard ants protect the tree that houses them by stinging seedlings that establish beneath their ‘ant-plant’ home. Apparently, the formic acid that the ants inject acts as a potent herbicide. For more on this intriguing behaviour, and the notion of ‘Devil’s gardens’ [a term not used by Zona], see Megan Frederickson et al. (Nature 437: 495–496, 2005; https://doi.org/10.1038/437495a), and the commentaries on that work by Andreas von Bubnoff, and Rhett Butler.

Introduction to a great – if rather macabre – acronym for ribosome-inhibiting proteins such as ricin, RIPs. For more on these, see Fiorenzo Stirpe et al. (Nat Biotechnol 10:  405–412, 1992; https://doi.org/10.1038/nbt0492-405), and Maddalena de Virgilio et al. (Toxins (Basel) 2(11): 2699–2737, 2010; doi: 10.3390/toxins2112699).

“Sugar beet farmers have learned to exploit fungus-inhibiting saponins (Maher Mohamed Abed El Aziz et al., J Nanomed Res. 8(1): 282-288, 2019; doi: 10.15406/jnmr.2019.07.00199) by growing a “precrop” of oats in the field in which sugar beets are to be planted” (p. 169). I couldn’t find a reference for that specific use, but for more on saponins from oats, see Jon Carter et al. (Appl Environ Microbiol. (8):3364-3372, 1999; doi: 10.1128/AEM.65.8.3364-3372.1999) and Anne Osbourn et al. (Proceedings of the Phytochemical Society of Europe 45: 121-128, 2000; https://doi.org/10.1007/978-94-015-9339-7_13).

“A few plants produce flowers in which the pollen grains germinate while still in the anther, grow down the filament and into the ovary, leading to fertilization without pollination ” (p. 176). I’ve not tracked down a reference specifically for this, but E Pacini & GG Franchi (Caryologia 35(2): 205-215, 1982; doi: 10.1080/00087114.1982.10796925) do report germination of pollen inside anthers in several species. And Sheila Johnson & Sheila McCormick (Plant Physiol. 126(2): 685–695, 2001; doi: 10.1104/pp.126.2.685) have identified a mutant of Arabidopsis – appropriately named ‘raring-to-go’ – in which pollen germinates precociously within the anthers.

Weaponised honey and grayanotoxins. For more on grayanotoxins, see Suze Jansen et al. (Cardiovasc Toxicol. 12(3): 208–215, 2012; doi: 10.1007/s12012-012-9162-2). For honey’s weaponisation, see here, Declan Henesy; Lex Leigh.

Perfume as a pollinator’s reward for some bees. For more on this specialist behaviour, see Peter Holland (Revista Brasileira de Entomologia 59: 62-64, 2015; https://doi.org/10.1016/j.rbe.2015.02.008), and Katharina Brandt et al. (2021), Front. Ecol. Evol. 9:727471; doi: 10.3389/fevo.2021.727471.

The concept of Dodsonian mimicry (Razi Brown; A Sankari et al. (Int. J. Curr. Microbiol. App. Sci. 8(4): 2969-2974, 2019; https://doi.org/10.20546/ijcmas.2019.804.343) – a flower that mimics another that is a good nectar source.

The shocking news that electric eels act as dispersal agents for palm fruit in the Amazon River. For which fact, Scott Zona & Andrew Henderson (Selbyana 11: 6-21, 1989) appears to be a suitable reference (although this cites a work of 1980 by M Goulding as the original source). A more informative statement – “the electric eel, swallow the stonelike seeds of palm fruits whole and digest the fleshy covering. The seeds pass through the fish’s gut and are defecated whole in a new location where, once the waters recede, they will not compete with the parent tree” – is provided in an unsourced article on vegetarian piranhas by Sy Montgomery.

I also learnt new words: herkogamy, and corbiculae (the proper name for bees’ pollen baskets); new terms – phugoid flight, drought deciduous, and ‘seed rain’ (Vern Grubinger), as an equivalent of pollen rain; and that water hyacinth and Leyland cypress have new scientific names.

All-in-all, Zona’s book is a veritable Aladdin’s cave of botanical delights!

Fascination and frustration…

There are many excellent aspects to A Gardener’s Guide to Botany, and I’ve been fascinated by all the new things Zona has introduced me to. But, equally, I’ve been frustrated by several features of the book, such as the absence of explicit cross-linking of references from text to sources of further reading, the paucity of sources to support the myriad of factual statements made, and the numerous internal inconsistencies. But, the feature of the book that has most frustrated me is the Index, which has the most eccentric layout I have ever encountered.

The Index

For A Gardener’s Guide to Botany, the index – this important feature of any factual book (Stephen Ullstrom) – is approx. 8.25 pages of 3-columned entries, from ‘animals’ [bizarrely, with no page number(s) indicated] to ‘weight of’. Curiously, no scientific names – nor even common names – for plants are included here. But, its most peculiar characteristic is the way in which entries are listed. For example, the second entry under ‘A’ is ‘alkaloids, and,’ [for which entry it bizarrely signposts us to p. 165]. Beneath that term we have many indented entries for topics such as ants, bats, bees, heterotrophs, and ‘window-leaf plants and,’ [I don’t know what the ‘and’ is doing here because each of these entries is effectively prefaced with the higher level entry of ‘alkaloids and’]. The next non-indented entry is ‘aquatic plants’. As for ‘animals’, with no indented topics beneath it, this is a stand-alone index entry. But, as for animals, it has no page number(s) indicated. If one wanted to find where these plants were mentioned in the book, you’ve got a bit of a problem [although p. 12 is a very good place to start re aquatic plants…]. That’s an indication of some of the idiosyncrasies of the index. But, it gets more frustrating…

‘W’ has a single entry ‘water’, although beneath that in an indented list are entries from ‘abundance of’ to ‘weight of’ [the last entry in the Index], via drip tips, hydrotropism, pathogenic fungi and, sound of, and transpiration. There are no entries for X, Y or Z. So how would one find pages that gave information about, say, xylem? Well, such entries can be found under ‘R’ for roots. Similarly for phloem – there is no entry under ‘P’, but in ’R’ under roots. That is irritating. It gets even more irksome if one wants to look up phosphorus. As you might by now expect, there is no separate entry under ‘P’ nor any mention of this element under any of the index entries for that letter [which only non-indented lead topics are photosynthesis, and pollination]. Instead, one will find phosphorus in two [at least two, I didn’t scour the Index for any other phosphorus entries that may have been hidden there…] places, under N as an item in the ‘nutrients’ entry, and under ‘F’ as an entry under ‘fertilizers’. But, that problem is compounded by the fact that phosphorus under ‘F’ lists two pages for phosphorus, whereas, phosphorus under N has 5 entries for this element, only two of which are the same as those for phosphorus under F. So, you’d arguably need to hunt down index entries for phosphorus in two different places to ensure that you’d found all the in-text mentions of this essential macronutrient. Interested in gymnosperms? To find out where those feature in the book, you need to look under ‘R’, reproduction. With nothing under ‘M’, where will you find mycorrhiza? Under ’F’ for ‘fungi.

Although I can’t imagine successfully using the index in this book to locate items of interest within the text, I could at least try and understand why the index has been laid out in the way it has if there was something – anything – in the book that explained why this had been done. But I can’t find any explanation for this eccentric indexing. And that only adds to my frustration.

Summary

With a few changes, A Gardener’s Guide to Botany by Scott Zona could be immeasurably improved. If that was done, it would be an excellent book on plant biology – for all and not just gardeners. To some extent it has the feel about it that I recall from books by Lancelot Hogben (JJ O’Connor & EF Robertson; William Hosch) – Mathematics for the Million (Chris Weeks), and Science for the Citizen (JDB; George Harrison) – which were intended to increase mathematical and science literacy, respectively, amongst the general public. Zona has the noble ambition of doing the same for the public’s botanical literacy: More power to him!

* Although mention of Chanel indicates luxury, highly-sought-after, expensive items (expensive perfumes came to my mind (Nathan Cherry), I didn’t know that the company made handbags. But I’ve discovered that they do, so that’s something else I’ve learnt from the book. Botany can introduce you to some unexpected information.

** However, the majority of the ‘Botanical tips’ – set-aside items found throughout the book (pp. 13, 75, 77, 90, 101, 129, 181) – tend to read more like ‘gardener’s tips’, and there’s plenty of mention of horticultural plants – as found in gardens or as house plants – to help provide gardening context to the botany.