Nigel Chaffey
Image: “Flower of Nelumbo nucifera, bean of India” by T Voekler.
Inspiration for Botany One stories
Several years ago I penned a piece giving some insights into the sources for my Plant Cuttings items that appear on the Botany One blog. It’s possible that item may provide some inspiration for others who aspire to pen their own pieces about plants – ideally for the Botany One blog site! – as well [Ed. – this is beginning to sound like an advertorial, but you are forgiven because we very much appreciate the attempt to encourage more contributors to the Botany One blog.].
To summarise that longish blog item, sources for plant-based stories are everywhere; almost every text-based item has a plant dimension, you just have to be alive to the possibilities – and maybe a little imaginative or ‘devious’ to tease out the botanical story. By way of a reminder of that – and hopefully to enthuse a new generation of Botany One blog contributors – I recently discovered another source for plant tales: the internet. Not that surprising to most of you I guess, and it’s certainly not news (!) So, to be more precise it’s the links that appear when one opens a new ‘tab’ in the web browser Firefox. Curated by “Pocket”, this facility allows the casual browser to “Discover the most thought-provoking stories out there”, and can be a surprising source of plant information…
For example, one may be intrigued to know “Why there’s no COVID in this year’s Christmas ads”*, and, having recently rediscovered the joys of chess, an on-line newspaper item about the Netflix series The Queen’s Gambit (and which is Netflix’s “biggest ever limited series”) was of interest**. As was an article entitled “The Feynman Technique: The Best Way to Learn Anything”***. And we could probably all benefit from advice on “How to be happier while working from home” during these days of covid****. No doubt, all vegetale-worthy items in their own way [for my plant ‘take’ on these, see *, **, ***, and **** below].
But, the item that really intrigued me was entitled “Lotus silk is one of the rarest fabrics in the world, but what makes it so expensive?”. What? Lotus silk – presumably a thread-like material from the lotus plant – is not something I’d previously heard of. Although probably peripheral to proper silk, the thread that’s ultimately derived from the leaves of mulberry, it wasn’t mentioned in Peter Coles’ book Mulberry, which I’d read recently. So, what is this lotus silk? One had to know more! And having read the article duly linked, I needed to dig further to slake my thirst for lotus silk-based information. Here’s where that journey of discovery took me…
What is lotus silk..?
A useful video tells us that the silk is made from long strands of fibres that are pulled out from stems of the lotus (Nelumbo nucifera). Unlike animal-produced, mulberry-derived silk, lotus silk is purely of plant origin. So, non-animal-sourced is this product, it has been termed vegan silk, which means it can be handled and worn by vegans (and may even be “The Most Luxurious Vegan Fabric On Earth”…).
But, why is lotus silk so expensive? Apparently, it can take two months, and the fibres from 9,200 plants to make a single lotus silk scarf (and up to 20,000 to make a costume). With such a lot of time and human expertise and craftmanship involved in the extraction, processing and weaving, these wearable items command prices up to 10 times that of a traditional silk scarf – e.g. US$200 for a 25 cm square item.
And wearing lotus silk items isn’t just a statement of the wealth of the individual, or a desire to be a trendsetter in fashion. Apparently, when clothed in lotus fibre fabrics “one feels calm, peaceful and meditative”, and this “also cures the wearer from headaches, heart ailments, asthma, and lung issues”. Fashionable, wearable medicine..? Fancy having a go at extracting your own lotus silk? Be advised, there are patents out there – e.g. this – that may present a hurdle to your own home-grown/home-spun efforts…
Lotus silk, it’s a wonderful story, and one that was completely unknown to me (and, I suspect, many of those reading this item?). But, since this is a blog item with a botanical focus, there are some important aspects of this story that need to be challenged – and corrected where necessary (as part of the writer’s aim to increase botanical literacy).
Botanical lessons: 1, what plant part provides lotus silk?
First is to identify unambiguously the part of the lotus plant that provides the fibres. Many sources just refer to ‘lotus stems’ (e.g. this) without any further qualification. Another account states, and somewhat ambiguously, that the fibres come from “stems of the lotus flower” [is that ‘stem’ the flower stalk of the lotus plant, or stems from elsewhere on the plant, and/but maybe the flowers, of the plant that is called the lotus flower..?]. Looking at a video of the fibre-extraction process, and bearing in mind the structure of the lotus plant, it looks to me like the stalk of the leaf that’s being used. Which interpretation is supported by one source clearly stating that “It’s the stems that reach up from the bottom of the lake to hold the leaves on the surface that contain the fibres”, and another by this phrase, “Lotus stem is meant collects the stem of lotus leaf”. The leaf stalk – technically known as the petiole – is not what is generally understood to be the word ‘stem’, which refers to “the plant axis that bears buds and shoots with leaves and, at its basal end, roots, or that which “connects the roots to the leaves”, or “is usually the above-ground erect ascending part of the plant body that develops from the plumule, bears leaves and flowers”.
The detailed account on lotus silk from Spinners World specifies that “Lotus fiber [sic.] is a natural cellulose fiber [sic.] isolated from lotus petiole”. Although it’s good to see the technical term used, its mention there potentially suffers from the problem that the word petiole is presented without explanation of what part of the plant is meant. Furthermore, mention of petiole in isolation – and hence its meaning – may in fact be rather misleading since earlier in that article we are told that the fibres are extracted from lotus stems, for which petiole is not another name. So, happy to have corrected/clarified that.
If you are tempted to think this is just a grumpy Botanist getting unnecessarily picky over highly-technical semantic niceties with articles intended for the general public, then let’s also be clear that there are issues with accuracy in peer-reviewed scientific articles on the topic of lotus fibres. For example, Hong Wei Zhang & Yong Lan Li refer to “lotus stalks” (Advanced Materials Research 146-147: 93-96, 2011; doi:10.4028/www.scientific.net/AMR.146-147.93). An article byDong-sheng Chen et al. also refers to lotus stalk but usefully qualifies that by stating that stalk refers to the “suspensor tube between lotus leaf and lotusroot [sic.] (Advanced Materials Research 476-478: 1948-1954, 2012; doi:10.4028/www.scientific.net/AMR.476-478.1948). And, lest you think the second article is better than the first – in terms of botanical exactitude, it should be pointed out that neither paper specifies the scientific name for the organism of study(!). I am, however, pleased to note that there are exceptions to this paucity of published plant detail, e.g. “Structural characteristics and physical properties of lotus fibers obtained from Nelumbo nucifera petioles” by Yin Pang et al. (Carbohydrate Polymers 85: 188–195, 2011; doi:10.1016/j.carbpol.2011.02.013).
At the risk of muddying the waters, there is at least one item out there stating that the yarn is made “by extracting and hand-rolling the fibres from the stems of the flower”. Flower stems are technically known as pedicels, and strictly-speaking are not stems [see above]. But, maybe both of those elongated plant parts – petioles and pedicels – can supply the necessary fibres? That seems likely, and there is also a source that uses fibres extracted from rhizomes – Yabin Zhang & Zhiguang Guo’s “Micromechanics of Lotus Fibers” (Chem. Lett. 43: 1137–1139, 2014; doi:10.1246/cl.140345)…
Botanical lessons: 2, lotus silk and bast fibres
Second, what exactly are the fibres that are turned into silk? One source tells us that “Botanically, the fiber is the thickened secondary wall in xylem tracheary elements”. This seemed rather unusual because other fibres from plant stems and stalks that I was aware of are categorised as bast fibres. Bast fibres, also known as phloem fibres, are found towards the outside of plant stems and closely associated with the phloem. Importantly though, bast fibres are fibres, a cell type within the sclerenchyma category which have largely support or protective roles, that is distinct from tracheary elements, which are involved in water-conduction. Lotus fibres therefore sound unusual – maybe unique? – amongst plant fibres.
The one study I found that reported detailed microscopic examination of the anatomy and origin of lotus fibres – Ying Pan et al’s “The anatomy of lotus fibers [sic.] found in petioles of Nelumbo nucifera” (Aquatic Botany 95(2): 67-171, 2011; https://doi.org/10.1016/j.aquabot.2011.05.002) – concluded that “The anatomy of lotus fiber shows that lotus fibers are quite different from other plant fibers in their source tissue and morphology. Lotus fibers are the helical thickenings in xylem tracheids and primitive vessel elements of lotus petioles”. That seems quite conclusive – and supports the unreferenced statement that this paragraph opened with.
Although anatomically different from other plants’ bast fibres, lotus silk is a member of that group of true plant-derived fibres ***** that includes jute, hemp, flax, ramie, kenaf, roselle, sunn, urena, and nettle******.
What plant theme unites the news stories in the 3rd paragraph?
Final thoughts for would-be contributors to Botany One
This item was a little longer than intended; I never know where the botanical journey will end once I’ve started to write these articles(!) (e.g. at the outset I didn’t think it would end up being a contender for Prof. Lena Struwe’s Botanical Accuracy blog). But, if it encourages just one person to write for the Botany One blog, then it’s been worth it. Although writing about plants – and in a Feynmanesque way that also shares that enjoyment – can be challenging, it can also be very rewarding (I learnt a lot from researching this item – and unearthed lots of fascinating material about such topics as the mythology, religious significance, and ethnobotany (e.g. also Nishkruti R. Mehta et al., Indian Journal of Pharmaceutical and Biological Research 1(4): 152-167, 2013; https://doi.org/10.30750/ijpbr.1.4.26), etc. of lotus I’ve been unable to use in this item…). But, above all, it should be enjoyable. If you enjoy writing the piece, one hopes that enjoyment – and understanding – will be communicated to others, and that will help to make the world a more plant-literate place. I wish you all the very best!
Those asterisked items…
* Plant angle? Carrots as noses for snowmen…
** Plant angle? Use of wood for wooden chess pieces, and wooden chess boards…
*** Plant angle? Nobel Prize-winning physicist Richard Feynman gives us ideas on how to communicate [plant] science – better(!)
**** Plant angle? “Bringing plants … into your home work space can have a significant impact”, in keeping with the “Attention Restoration Theory”…
***** Why no mention of cotton or kapok here? Because the materials of the same name obtained from those plants aren’t bast fibres, but single-celled hairs from the external surface of the seed–heads, and categorised as seed fibres. Interestingly, bast fibres can be extracted from the stems of cotton plants (e.g. Alban Yzombard et al., Textile Research Journal 84: 303-311, 2014; doi: 10.1177/0040517513495949) [Ed. – whether that spinnable fibre should also be called cotton is a matter for another time and place…]
****** Where is sisal? This fibre comes from a monocot (all other fibres listed above are from dicots). Since bast fibres come from dicots, sisal is not a bast fibre; it is a leaf fibre (as is abacá from banana), as is agave).
******* it’s only just occurred to me(!). Lotic is, presumably, the adjective from the noun lotus and can be applied to lotus-like properties, etc. Lotic is also the ecological term that refers to “any kind of moving water, such as a run, creek, brook, river, spring, channel or stream”, or “relating to or living in actively moving water”, or “inhabiting or situated in rapidly moving fresh water”. However, the usual aquatic habitat of the lotus plant is “flood plains of slow-moving rivers and delta areas”, or “large lakes”. These slow-moving bodies of water are termed ‘lentic’ environments, i.e. despite its name, the lotus is not found in lotic areas(!): Curious. Botany, not always straightforward, which is why it’s always surprising and endlessly fascinating…
[…] A thread about ideas for Botany One plant stories […]
As I recall, bast fibers are the clusters of phloem fibers from dicots with hemp and linen being perhaps the two best known. What I learned as “structural fibers” were entire vascular bundles from monocot leaves (manila hemp)(Musa textilis), and thus being rather larger in diameter and coarser than bast fibers. However I do not know whether lotus fibers are obtained from petioles (they would be the most plentiful part) or flower pedicels. Thanks for an interesting botanical discussion. So rare these days.
Dear Prof. Armstrong,
Thank you for your comments, observations, and appreciative words.
As you hint at, the whole ‘what is a fibre?’ story gets quite tangled when trying to marry the terms and differing points of view used by textile workers and plant anatomists.
Cheers,
Nigel