Using DNA to identify the plants used to make tapa

Using DNA to identify the plants used to make tapa

Tapa, or barkcloth, is an important textile in the Pacific. Tapa is made from the beaten inner bark of some plant species, but once the tapa is made then identifying which plant species was used is difficult. Our genetics researcher Lara Shepherd teamed up with Catherine Smith from the University of Otago and colleagues to create a DNA reference database for identifying the plants used to make tapa.

Tapa was an important material in the Pacific before the 19th century but its production declined when European fabrics became readily available.

Given its portability, tapa was a popular souvenir for early European travellers. Consequently, there are many tapa artefacts in museums worldwide but information about their origins was not always recorded.

Identifying the plants used to make a particular tapa can help determine where it was made.

A piece of tapa cloth with brown, black, and cream lines painted on it. It's sitting on a black background.
Kapa (tapa) (bark cloth), 1770s, Hawaii, maker unknown. Gift of Dr P. Adams, 1947. Te Papa (FE005247)

Round the mulberry bush

Most tapa in the Pacific was made from paper mulberry but a number of other species were also used including banyan fig, hibiscus and breadfruit. Māori brought paper mulberry with them to New Zealand but our cooler climate meant that the plants did not thrive.

However, tapa, known as aute in te reo Māori, was also made from some native New Zealand plants including houhere (lacebark) and autetaranga (sand daphne). There are no confirmed surviving examples of pre-European aute but the practice has been recently revived.

A leaf is sitting on a cream-coloured card with stamps and a identification label underneath it.
Aute collected 8 October 1769 by the botanists Joseph Banks and Daniel Solander on Cook’s first voyage. They recorded at the time that it was cultivated in the northern parts of New Zealand but was rare. H‘eaute [aute/paper mulberry], Broussonetia papyrifera (L.) Vent., New Zealand. CC BY 4.0. Te Papa (SP063948)

Methods to identify the plants used to make tapa, such as microscopy, have had limited success to date. Therefore, we decided to explore the use of DNA identification.

First, we made a list of all the plants used to make tapa, based on indigenous knowledge. We then made a reference library of DNA sequences by gathering published DNA sequences from these plants.

One particular piece of DNA had already been sequenced for many of the plants used for making tapa. We then sequenced the same fragment of DNA from as many of the plants that had not yet been sequenced as we could find. 

We managed to locate some of these plants in our herbarium and others were supplied by Ōtari-Wilton’s Bush and the Auckland Botanic Gardens.

Bright yellow flowers on a green bush. The leaves are quite rounded.
ʻĀkia or Hillside false ohelo (Wikstroemia uva-ursi) is one of the endemic Hawaiian plants used to make kapa (tapa). Photo by David Eickhoff via Flickr. CC-BY-2.0

Written in our DNA

Analysing our reference DNA library showed that the DNA sequences could identify most of the plants to genus.

Many of the species within a genus, such as the species of houhere (lacebark), could not be distinguished from one another. This is likely a result of hybridisation, which moves DNA between species.

However, identification to genus is still sufficient to determine the origins of some tapa, particularly those made from native plants from New Zealand and the Hawaiian Islands.

Clumps of white flowers on a bush that has big leaves with jagged edges.
Lacebark (Hoheria populnea), an endemic New Zealand plant used for making aute/barkcloth. Photo by Avenue. Dual-licensed under the GFDL and CC-By-SA-2.5, 2.0, and 1.0

The second aim of our study was to compare different methods for extracting DNA from tapa. We examined a number of methods that have been used by other researchers that involve removing and destroying small pieces of the tapa (destructive methods).

We also tried several non-destructive methods but these were largely unsuccessful. However, we did determine the best destructive DNA extraction method, which will be useful for future studies.

We are now hoping to use both DNA and PLM microscopy methods to identify the plants in a collection of important pre-contact aute held at Otago Museum, which has long been thought to be made from endemic New Zealand plants.

Further reading

Shepherd LD, Smith CA, Lowe BJ, Campbell D, Ngarimu R (2021) The identification of plants used to make tapa artefacts: development of a reference DNA database and trial of non-destructive DNA extraction methods. Journal of the Royal Society of New Zealand.

1 Comment

  1. Very interesting. It would be great to see what aute made from houhere looked like and interesting to know what sort of articles were made from this fabric. I’m looking forward to the results.

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