Symplocos – A Plant Mordant

Symplocos is a plant species that accumulates alum mordant. It is one of number of plants that grows in acidic soil around the world, and thus is able to absorb available aluminum from the ground. Although different parts of the tree absorb alum, it has been determined that the fallen leaves have a high concentrations of alum and are the most sustainable source of mordant. By harvesting the fallen leaves, no damage is done to the tree. These leaves can be used as an alternative and highly effective source of mineral alum, while also imparting a pale yellow color to the fiber. 

One variety of symplocos is native to Indonesia and utilized by weavers and ikat dyers with when dyeing red with morinda (Morinda citrifolia) on cotton. The Bebali Foundation has been studying the mordant process for a number of years and has made symplocos available to dyers around the world, while supporting the local women who gather the leaves. Michel Garcia worked with the foundation to develop recipes for both protein and cellulose fibers. All of these recipes are available online at The Plant Mordant Project.

I have experimented with symplocos many times with great success. Recently I have been introduced to a variety of symplocos  (Sympolocos tinctoria)  that is native to the southeastern United States. It is described as a small tree or shrub, “deciduous or weakly evergreen”. It is also known as “horse sugar” or “sweetleaf” because horses are attracted to the sweet leaves of the plant. As I researched, I read that it grows in “very acidic soils”. It is sometimes described as a source of yellow dye, but nowhere did I read that it was a source of alum. 

Leigh Magar, a textile designer and dyer, brought me a handful of leaves last year that she collected at her home near Charleston, South Carolina. I proceeded to test the leaves as a source of mordant, comparing them to the symplocos that I have from the Bebali Foundation, and also to mineral alum. I ground the leaves and used Michel Garcia’s recipe. The results were very good. 

weld (2)
Mordant only applied to wash-fast wool knit: 1.) no mordant, 2.) mineral alum mordant, 3.) Bebali symplocos mordant, 4.) South Carolina symplocos mordant
weld 1
Weld and madder dyes applied following 1.) no mordant, 2.) mineral alum mordant, 3.) Bebali symplocos, 4.) South Carolina symplocos
sympolocos leaves
South Carolina leaf on left, compared to the larger symplocos leaf from Bebali. Both leaves were ground fine before applying them to the textile.

Last month I was finally able to travel to Leigh’s home in South Carolina to see the plants myself and to gather some of the leaves. Our regional variety has leaves that are smaller than the Indonesian variety but they are shed in much the same way. The leaves yellow as they age and drop from the tree. They are easily gathered from the tree at this time. Leigh tells me that shedding seems to be more more prevalent in the spring, although the tree sheds its leaves all year long.  

Older leaves yellow on the tree before falling to the ground

I am currently reading (and very much enjoying) Braiding Sweetgrass by Robin Wall Kimmerer. In the chapter entitled The Gift of Strawberries the author talks of wild strawberries as unexpected gifts received from the earth. Finding alum in a plant is very much like a gift – to be received gratefully – but not to be turned into a commodity. I will treasure this gift of alum and appreciate Leigh’s generosity in sharing it,  but it will not replace the mineral alum that I purchase from a supplier.

And a couple notes on our book: The Art and Science of Natural Dyes. First of all, I am very appreciative of the many notes and emails I have received from so many of you. It is exciting to both Joy and me that the book is finally out and truly being used. 

There is one important omission on pages 169 and 170. The mordants used for the photos of the dyed samples should cross reference mordants #1 – #5 (top to bottom), from the mordant mixing chart on p.150.

p 169 corretion

And about the spiral binding – we chose the binding very intentionally so that the book would open easily and stay open. The book is meant to be used, referred to, and likely to get stained, like a much used cookbook. Many of you have told me how much you love the binding but I have also heard from a few of you that pages can easily slip out of that spiral. A dyer in Australia showed me a perfect solution; she threaded a piece of cotton yarn through the binding, locking the pages in. I have now done this to my own book and would suggest that you do it to yours as well. 


51 thoughts on “Symplocos – A Plant Mordant

  1. Thank you! Good to know. Dorothy Yuki

    On Thu, May 2, 2019 at 10:16 AM Natural Dye: Experiments and Results wrote:

    > Catharine Ellis posted: “Symplocos is a plant species that accumulates > alum mordant. It is one of number of plants that grows in acidic soil > around the world, and thus is able to absorb available aluminum from the > ground. Although different parts of the tree absorb alum, it has b” >

  2. Hi Catherine, The insttuctions that I read from Indonesia were very complcated. Do you have simple directions ? Where do you buy symplocos ? Thanks, Sara Burnett

    Sent from my iPhone


    1. Sara, It’s pretty straightforward, though it does require an extra step of extracting the alum from the leaf matter. I used the recipes published on the plant mordant site, using 50% w.o.f., boiled it for 30 minutes and then proceeded to mordant.

      1. I agree. On the Bebali website, it says that you should ‘soak the yarn or fabric in a solution of 10% WOF turkey red oil in water (??) at 60 degreesC for at least an hour. This is confusing. How do you soak the fiber in turkey red oil in water? Does that mean soak it in a mixture of the oil and water? The next step is even more confusing. First it asks to soak the fiber in gall nut extract for 60 minutes. Then immediately after it says to allow to steep overnight…

        SO, I’m wondering if you can 1) bypass the turkey red oil step (I’m new to dyeing and not sure what that is, I would also be afraid to soak textile in oil, yikes!) 2) is a tannin soak necessary, or can that be bypassed? 3) Is it possible to just follow their step 3, whereby it says to boil the symplocos for 60 minutes, then soak the fiber in this liquid for 30 minutes to Mordant, rinsing after.

        Sorry if my question is complicated. I just purchased some symplocos and I’m ready to use it this week, so I’m writing out all of my preparation details tonight so by the time I’m ready to dye, everything is in place.

        By the way, THANK YOU THANK YOU THANK YOU for all the work you do. I find myself returning to your instruction (book/website/other websites where you are a guest contributor) over and over again and you have helped me immensely! My indigo vat worked on first go! And has continued to produce the best results without ANY issues at all. She dyes deeply, consistently and reliably and we love each other 🙂


      2. (One last thing, sorry! Can you use a mordant bath multiple times? For instance, if I made an alum or symplocos mordant bath, could I store it for later use if the fiber doesn’t soak up the entire amount? THANK YOU!)

      3. You are right, the Turkey Red oil is made into a solution of oil and water. It is a water soluble oil (sulphonate castor oil).

        Can you skip the oil step? I have not used the symplocos mordant extensively on cotton so I cannot say whether the oil will help the tannin and the sympolcos mordant attach to the fiber. But the tannin step is very necessary! When mordanting with tannin plus alum/soda ash or tannin plus aluminum acetate, Joy and I found that the oil did not improve the uptake of the mordant but it may be different with the symplocos.

        We calculated that there is about 1/2 of the original mordant left in the bath after mordanting with mineral alum. I’m not sure that would be the case with the symplocos. Also, I don’t know if you can store this organic material. Much like a dye, the plant material might begin to mold and deteriorate. You may just need to do some testing with this.

  3. Thank you Catharine once again for freely sharing your knowledge with us about the tests you have done with US Symplocos, and your insight and candour about not replacing your mineral alum. It is so important that we recognise that some of nature’s resources are finite and to choose the one we have ready access to in a sustainable way. For me that is also mineral alum, but when I was living in Malaysia, it was Symplocos.
    I am also enjoying using your book and appreciate the care you took with getting the colour photos just right!👏🏻🙏🏻

  4. Thank you Catharine, is it not fantastic to find new plants that can be used as mordant. I wonder if other plants growing in very acidic soil would also be rich in aluminum. I am thinking of Rhododendrons, and Azalea and other members of this family. We would need to have a chemist test this.

  5. Thank you for the information about sympolcos. I tried it once and will use it again. Thank you, too, for your amazing book. I’ve learned so much from it already after just skimming through it. I look forward to reading it in more depth and using it in my own dye practice. I smiled when I read your comment about “Braiding Sweetgrass.” I read it recently, and it’s now on my short list of very favorite non-fiction books. It’s a gem :).

  6. Thank you for sharing your experience! I live in France and I use Symplocos from Indonesia, excellent results. Could you tell why: ” but it will not replace the mineral alum that I purchase from a supplier.” Thank you!

    1. Maybe I should have said it will not replace ALL of the alum that I use. The symplocos from Bebali is fabulous and supports an excellent program. The South Carolina symplocos is not a viable enterprise – more like “found treasures”. I will continue to use the Bebali symplocos for some things but cost and convenience sometimes wins out – and I also feel compelled to do much of my testing using the more common mineral alum.

  7. I wanted to check for the book “Braiding Sweetgrass”, by Laura Wall Kimmerer, and I found: “Braiding Sweetgrass: Indigenous Wisdom, Scientific Knowledge and the Teachings of Plants”, by Robin Wall Kimmerer. Is that the same book? Thank you

  8. I was visiting a dyer in Teotitlan de Valle last month, and he showed me a plant that he uses the leaves as a mordant. The name is pronounced ocasila (oak a see la). I wonder if you know anything about the plant. I’ve been unable to find anything about it. Would it be better to email you?

    I’m happy to know there is a symplocos plant in the US. Unless I travel to the region it grows, I won’t be gathering it, so it is safe from me. I recently listened to the author read her book Braiding Sweetgrass. Her calming voice perfectly sets off the messages. Get the audio version – it’s magical.

  9. I am not absolutely sure, as you may not have the correct spelling but “ooca” is Spanish for “oxalic”. It may be a plant that contains oxalic acid, and although not truly a mordant, the acid is used for some processes to increase the dye take-up on wool, as an alternative to using a mordant. Michel Garcia introduced it to dyers in Oaxaca in the Slow Fiber Studio DVD. Joy and I also talk about it in the book. Ana Roquero wrote an excellent book on dye plants of Central America, Tintes y tintoreros de America. It is in Spanish, which I don’t read well, but I did figure that out.

    1. That is at least a clue. He was using it with cochineal that day. He said he used this plant’s leaves instead of alum. I saw a copy of Tintes y Tintoreros in a private library in Oaxaca but have been unable to locate one for sale. The search continues. I was thinking I could find a plant here in the same family, but first I have to name the plant.

  10. That makes total sense, assuming he was dyeing wool. A mordant is not required when dyeing wool with cochineal. The oxalic acid would acidify the bath, and modify the color – making it warmer. That is why lemon or lime juice is often added to the cochineal bath.

  11. Thank you Catharine,
    Symplocos was the first dye plant I discovered in my woods and indigo the second,along with Indian hemp,wild silk; gifts from Mother Nature that I use for my small collections of dresses and textile art. I’ve thought of selling these dye plants but realize that gifts from nature should be respected; therefore I collect what I need. I am grateful for these gifts and for your knowledge.
    thank you for sharing!
    Leigh Magar

  12. Fascinating as always! I am one of those very much enjoying the book, and equally thrilled to be able to recommend it to other dyers! Thanks for clarifying about the mordant printing images too.

  13. Hi Catharine. I’m always nervous about using alum. I dont use aluminum based deodorant or aluminum cooking tools at all. I am new to dyeing and I want to be able to have success with color and lightfast BUT, I am hesitant to use alum for obvious reasons. Is the alum in this plant considered less toxic? Do you have any other suggestions for non toxic mordants (mainly for cellulose, linen primarily, cotton secondarily). I would appreciate your guidance. Thank you!

    1. I can understand your apprehension. On the other hand, it will be nearly impossible to achieve good color on cellulose fibers without the use a mordant. Alum is the most benign of the mordants. If you are concerned about absorption of the aluminum into your body, then wear gloves during the mordanting and rinsing processes. Once it is attached to the textile, the aluminum will not “dissolve”: again. The symplocos does contain the aluminum mordant, absorbed from the soil in which it grows.

      1. Thank you for your response! This makes me feel better about using alum. I will try symplocos though. I like the idea of using something more natural. And it may be time for elbow length gloves! You are such a gem, thank you for being here for all of us! xoxo

  14. Wonderful to hear about a regional bio-accumulator for aluminum! Have you ever come across any surveys listing different plants and the metals they sequester? I’m curious to find out if there has been research on the subject and to establish a listing of “local plant mordants” for dyers.
    Huge fan of the new book by the way. Thank you so much for publishing such an in-depth and concise manual.

    1. Hi Graham,
      I have not come across such a survey or list. Aluminum is only absorbed IF it’s in the soil, and IF the soil is acidic, and IF the plant is a bio-accumulator – so that’s a lot of things that have to come together in order to make a local plant mordant. Camellia leaves, tea leaves, symplocos, and club moss are some of the plants I know about. But I have used club moss that resulted in no mordant at all being deposited on my textile, so I guess the conditions were not right. I’m not sure where it was grown as I purchased the dry plant material. It is an interesting topic and I’d like to know more, too. Thanks for your comment about the book. I still think of it as a work in progress….

  15. obrigada por tanta dedicação e disponibilidade em repassar todas suas pesquisas . Recebi seu livro esta semana e ja estou usando como se fosse uma Biblia ….

  16. Hola, yo aprendí a trabajar con taninos con Michel Garcia, y creo que es un investigador nato, fantástico, pero me gustaría saber si tu libro lo tienes en pdf, porque así podría traducirlo aunque sea mal, tengo demasiado que leer en inglés y me cuesta bastante, el blog lo traduce google y es muy cómodo, las palabras que siento que están mal traducidas las busco.
    Te recomiendo un libro si lees francés,”Colorants, encres and pigments des végétaux du XXIs” de David Damour, creo que puede ser de tu interés aunque está en parte enfocado a la pintura con colores vegetales, pero da muchas recetas interesantes.

    1. I am sorry, Maribel, but the book is only available in print form. That would be a good question for the publisher as well as a translation. Thank you for the recommendation of the David Damour’s book but my French is not good enough to read it well.

  17. I enjoyed this blog post as I’m looking into using symplocos as a natural alternative to alum. Thanks for your info! I also noticed that the name of the author for Braiding Sweetgrass is incorrect – The author is Robin Wall Kimmerer, not Laura…

  18. I have an question, 2 years after this was written. I will dye linen fabric (predyed off white, presumably synthetic dye) with ceriops tagal, a mangrove root high in tannin. The ectract is boiled in water then aged for a month and yields a red brown. The fabric is dipped in air temperature dye multiple times. Traditionally, in Indonesia, symplocos is used as a mordant. Since the dye itself is high in tannin, would a tannin treatment before mordanting be necessary? Or would symplocos not adhere to the fabric without the pretreatment?

    1. Yes, the tannin step prior to the mordant application is still necessary. Otherwise the aluminum in the symplocos will not attach to the cellulose textile and you will not get the full color from your tannin-rich dye material. It is not the same if a tannin is applied after the alum.

      1. I have dried leaves of Rhus copallinum (winged sumac). Will that suffice as a tannin, whether I use symplocos or alum?

      2. Thank you. I’ll go for the sumac, then. Since the original post, have you found that turkey red oil helps the uptake of symplocos? I have not even found a source for it.

      3. The oil is sold as sulfonated castor oil, which is castor oil that has been treated so that it is soluble in water. It is used by soap makers Joy and I did experiments with it and did not see a significant amount of difference when the oil was used so we left that out of the process, although I know it is used in traditional practices.

    2. Again, thanks. I am a soapmaker (never used that, or maybe I should look at my castor oil again?) If it’s not necessary, I can skip that and save some time and expense.

      This whole process is new and exciting for me. I am a wool yarn dyer, but have not dyed cellulose fabric.

  19. Hello Catherine! When you did your turkey red soak, did you rinse and then dry or just dry?

    Also, for all of the steps, how dry should did you let your fabric get: bone dry? Or just rung out until it’s not dripping?

    I’m a complete novice to this art form and appreciate your help (☝◞‸◟)☞

    1. There may be some tannins in the symplocus leaves but if applying the mordant to cellulose, you still need to do the tannin step prior to the application of mordant. In Bali, where the leaves are used traditionally, they apply oil before the application of tannin. Michel Garcia also recommends it at

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