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Natural Dyeing and EcoPrinting with Rhatany Root

Updated: Feb 28, 2022

Discover more exotic natural dyes with surprising results, Rhatany roots could be just what you have been looking for in your natural dye stash!

Peruvian rhatany (Krameria triandra): flowering and fruiting plant with roots and fruit segments. — Coloured lithograph after M. A. Burnett, c. 1843.

Lately I have been reading many (great) books and I am coming across some dyes I never heard of before. It is so nice to learn new things and expand the horizon a bit!

The first time I ever noticed the mention of Rhatany roots as a dye plant was in H. Schweppe's gem of a book (sadly only in German) "Handbuch der Naturfarbstoffe". If you have basic German you will manage with this book and it is a must have in your library with over 900 different natural dyes described. Even if it is no longer in print, you should be able to find a reasonably priced copy on Abebooks.

Schweppe puts Ratanhia Krameria trianda in the list of condensed tannins, which is already great because that means it should be rather light fast, not 'need' any extra mordants and be a good match for cotton. Enough brownie points for me to get my hands on some, and start looking at the dye potential.

Where does it come from?

Rhatany (Krameria trianda) grows in Bolivia, Equador, Chile and Brazil, in areas over 1000 meter altitude. Most of the dye stuff is collected and exported from Peru. The powerful reddish brown roots are a great match for the rocky terrain of the Bolivian and Peruvian Andes.

The plant was mentioned first in 1779 by botanist Hipólito Ruiz López (1754-1815) as a dye plant with the same dye potential as Acacia catechu. The name rhatany comes from the Peruvian Quechua language and is translated as “plant that crawls over the ground”.

Fun Fact: Rhatany is an opportunistic hemiparasite: it uses diverse (and quite random) plants as hosts to draw water and nutrients. To attract bees, the flowers do not produce nectar but an oil in special glands called elaiophores.

Rhatany Root - Krameria triandra

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Other uses

Rhatany red is becoming increasingly popular in use in cosmetics. The high tannin content makes it a great antibacterial, astringent and antioxidant used for inflammations of the throat and as a mouthwash. It is well known to local populations for maintaining healthy teeth. An article by Beryl B. Simpson mentions that between 1820-1920 Rahatany root was a rather common medicine. (1)
It was a tradition among women in Peru to clean and whiten their teeth using Rhatany root sticks.
A strong tincture of these roots is used in Portugal to add roughness to brandy and port wines.
The neolignans present in Rhatany root, particularly Eupomatenoid, have also shown antimicrobial activity against bacteria, fungi and anaerobic strains

The colourants

The red of the fruits and flowers are proanthocyanidins like propelargonidina and procyanidins and will not give you any joy in dyeing.

The colour is in the roots:

8-18% Rhataniatannic acid which is very similar to catechu-tannic acid.
Oxidation forms Rhatany red (C26H22O11), which in combination with a light alkaline environment gives us beautiful reds. (this is just a fancy way to say you should add soda ash to your dye bath).
Proanthocyanidins (not light or wash fast so we do not count on those for lasting colour)
Flavonoids, which what will give warm orange if you are dyeing in a Ph neutral or acidic bath.

How to dye:

Rhatany will dye silk and wool without a mordant. Using alum gives stronger shades that will be more light fast. For linen and cotton use alum as a mordant. Rhatany root is available in chips or in powder.

As a rule: always soak root dyes before use unless it is an extract, because then they already did all of that for you. I left the rhatany roots in water for three days before I started to heat the dye bath. I also tried finely ground roots to see how it would dye if I skipped the soaking.

Slowly bring the dye bath to a rolling boil with the fabrics inside. If you are dyeing wool and silk you may opt to boil without fabrics for an hour, and then let the bath cool down to 60ºC and only then add and keep the fabrics in for a longer time.

The roots bits really only released colour once they were getting heated, but once they did they gave a LOT of dye.

We had lovely results with 90 minutes of fabric in the dye bath.

The dye results: Shades look a lot like fabric dyed with madder.

The powder gave brown, and it is clear that soaking would have made all the difference.