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  • Māori have many traditional uses for harakeke (Phormium tenax) such as the making of traps and fishing nets and the weaving of whāriki (mats) and kete (baskets). Harakeke is also important for the production of textiles, for example, muka, a prepared flax fibre, is frequently used as the base for kākahu (clothing) or korowai (cloaks).

    Rangi Te Kanawa (Ngāti Maniapoto), a textile conservator at The Museum of New Zealand Te Papa Tongarewa, faced the problem of rapid deterioration in the harakeke kākahu. Of particular concern was the rapid deterioration of the fibres that had been dyed black using a traditional method where the fibre is immersed in paru (mud).

    Te Papa has the largest collection of Māori textiles in the world. Amongst these important taonga are 400 kākahu, and most utilise a muka backing with feathers, dog skin and other decorations woven into the front of the kākahu.

    For Māori today, these textile taonga are not only a living connection to their ancestors, they’re also a rich repository of knowledge about crafting and weaving techniques.

    Te whāinga – the goal

    Rangi needed to find a way to prevent the deterioration in order to protect these precious taonga tuku iho and their valuable intellectual property for future generations.

    Rangi teamed up with Dr Gerald Smith, Associate Professor of Chemistry at Victoria University. Gerald specialises in the chemical and physical processes responsible for the degradation of organic materials and teaches a course in heritage material science.

    Rangi, who comes from a long line of weavers, brought specialised mātauranga (knowledge) accumulated over generations within her whānau. Rangi and Gerald used their combined knowledge to identify what was responsible for the deterioration of the textiles and how they might work to counteract it.

    When I began my training as a conservator, I realised then that there was a problem – a problem that I’d been witness to as a child, watching mum and nana put this fibre muka into mud.

    Rangi Te Kanawa, textile conservator, Te Papa

    Rangi and Gerald’s work was able to identify the chemical reactions causing the damage – the breakdown of acetic acid produced by the harakeke that, when released, further accelerated the disintegration of the textile. The black dyed fibre was significantly more vulnerable because the dying process introduces tannins in the paru.


    Having determined the key cause of the damage to the textiles, Rangi and Gerald began to research a possible solution to either neutralise or reduce the acetic acid.

    Rangi came up with a novel solution using alginate from seaweed. Gerald was able to test this by accelerating the deterioration of fibres in an oven. The fibres that were pre-treated with the solution – and those that weren’t - were then tested using a gas chromatograph. This showed that the alginate solution neutralised the acetic acid.

    Gas chromatograph

    An important tool in Gerald’s lab is the gas chromatograph.

    Atmospheric chemist Dr Katja Riedel also uses a gas chromatograph. In the above video she explains how it works.

    Rangi is now using the innovative alginate solution in her work conserving the kākahu at Te Papa.

    Other indigenous cultures also use chemically-identical dying methods, and the solution is now being used by conservators around the world.

    A kaupapa Māori approach to harakeke research

    Dr Bronwyn Lowe at Otago University worked with Māori weavers to investigate a collection of harakeke plants at the Dunedin Botanic Garden.

    Because of the cultural significance of harakeke, the research on the collection was done using a kaupapa Māori approach. This meant that the involvement of Māori weavers Kahutoi Te Kanawa, Roka Ngarimu-Cameron, Anna Gorham and Christine Holtham was paramount. The weavers chose which harakeke plants would be studied in detail and assessed the weaving properties of each one. The weavers also worked with their people to make decisions about how the results would be disseminated. Read more about this research in this article, Harakeke under the microscope.


    Harakeke has many medicinal uses that have been passed down to modern Māori from their tāpuna (ancestors). Read more about rongoā and medicinal native plants, in this article, Rongoā Māori.

    High school student Chris Ryan researched the medicinal properties of kawakawa, read about it in this Connected journal article.

    Using rongoā Māori is an activity for students learn about rongoā Māori through a silent card game.

    Explore our collection of Rongoā Māori resources on the Science Learning Hub with helpful notes for teachers. Login to make this collection part of your private collection – just click on the copy icon. You can then add additional content, notes and make other changes.

    Nature of science

    Using science to understand problems and find solutions often leads to innovative discoveries and technologies. Combining knowledge of historic practices with new scientific understanding gives us insights into why these historic practices worked and how to use and enhance them today.

    Related content

    Black is back is an Connected journal article featuring Dr Rangi Te Kanawa, and has supporting teacher resources, from the Ministry of Education’s Connected series.

    Useful links

    Te Papa’s kākahu researchers – Learn more about Dr Rangi Te Kanawa and her fellow kākahu researchers Hokimate Harwood and Dr Patricia Wallace at Te Papa.

    Listen to this Radio NZ programme Dr Rangi Te Kanawa: working to conserve our taonga kakahu from May 2022.

    Watch this Te Papa video on YouTube of Rangi talking about her work and how her upbringing influenced her work in conserving the Māori cloaks in Te Papa's collection.

    In the video, ethnobotanist Sue Scheele and kaitiaki Katarina Tawiri show some of the flaxes and their different properties. Harakeke samples for this research came from a collection of traditional weaving varieties of harakeke at Manaaki Whenua – Landcare Research. Explore the different harakeke in the National New Zealand Flax Collection and learn more about them.

    Project Mātauranga

    Watch Series 2/Episode 1: The Problem with Harakeke

    Project Mātauranga is a television series that investigates Māori world views and methodologies within the scientific community and looks at their practical application. Each of the 13 episodes in series 2 shows how western science and Māori knowledge systems are combining to provide solutions to a variety of challenges.

    The Science Learning Hub thanks Scottie Productions for allowing us to host these videos.

      Published 17 December 2015, Updated 28 February 2023 Referencing Hub articles
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