A team from the Australian Institute of Botanical Science has collected about 400 plant specimens on the recent Australian Museum-led expedition to Norfolk Island, helping the community identify new weeds that potentially could cause havoc to local ecosystems.

Botanic team on a mission to fill knowledge gaps

Norfolk Island, about 1,600km north-east of Sydney, has a diverse environment and provided a great research opportunity for a team from the Australian Institute of Botanical Science (Institute).

The Institute team’s mission was to collect herbarium specimens to help fill knowledge gaps of Norfolk Island’s flora, focusing on areas where no or few collections have been lodged in Australasian herbaria, such as the National Herbarium of New South Wales.

Although weeds are not part of Norfolk Island’s endemic and unique flora, they have the potential to threaten the local ecosystem and became a matter of interest for the researchers. The threat of Oxalis pes-caprae (Soursob), which is a very serious, pernicious weed, was of particular concern.

Senior Botanist Marco Duretto said as well as Oxalis pes-caprae, Soliva anthemifolia (Button Burweed) and Hypochaeris albiflora (White Flatweed) were provided to the team by locals and are new records for Norfolk Island. A new species of fern in the genus Blechnum was also a significant find, and may represent a new, possibly naturalised, species for the island.

While the researchers had their eyes on weeds, team member Honorary Research Associate Matt Renner collected bryophytes (mosses, liverworts and hornworts), which are his research speciality. Matt’s collections significantly expanded the knowledge of the bryophyte flora of the region with first records of families, genera, and species for the region commonplace.

All up the team made c. 400 collections (including 160 bryophytes) of c. 140 species and the numbers of species will increase as identifications are finalised, especially that of the bryophytes.

Research team (L-R) Andrew Orme, Marco Duretto, Mel Wong and Wayne Cherry

Research team (L-R) Andrew Orme, Marco Duretto, Mel Wong and Wayne Cherry.

Image: Andrew Orme
© Australian Institute of Botanical Science

Bryophyte expert Matt Renner

Bryophyte expert Matt Renner.

Image: Meagan Warwick
© Australian Museum

Collaborating with the community to improve conservation

The team also included Senior Technical Officer ID Counter Andrew Orme, Digitalisation Officer Mel Wong, and Plant Information Network Officer Wayne Cherry. They joined forces with the local community, the Australian Museum, Parks Australia and the Auckland War Memorial Museum in a biological survey covering many animal and plant groups.

Marco said building close contacts with the local community to develop long-term relationships was very important in helping the team to discover new flora.

“The local Flora and Fauna group on Norfolk Island has been meeting for many years and has built up a wealth of knowledge,” Marco said.

“We were lucky enough to be able to engage with some of them and hopefully form some long-term relationships so that together we can continue to build on the knowledge and understanding of Norfolk Island’s flora."

“Often scientists like us will sometimes go about our work and not connect with locals but both Museums and the Gardens were very keen to build long-term relationships with the local community.”

“This Oxalis weed is a real scary one – it’s a spectacular species and beautiful to look at – but it has underground bulbs and is a very serious weed. Once it gets into local areas it’s hard to get rid of. It forms monocultures because other things that live on the ground next to get excluded."

“Local people knew it was there, but records didn’t exist in herbaria collections, and now we have a permanent record for this species of weed on Norfolk Island. And our confirmation of the identity will help the local council take appropriate action to eradicate it before it becomes an issue,” Marco said.

Future research on the collections will no doubt identify species known previously from other areas, but we also anticipate the discovery of several species that will be new to science. Marco Duretto

Oxalis pes-caprae (Soursob)

Oxalis pes-caprae (Soursob).

Image: Andrew Orme
© Australian Institute of Botanical Science

Why weed knowledge is important

Weeds are very important in terms of economic and conservation impacts because they are a major threat to native flora communities.

The weeds were brought to Norfolk Island by various settlers, from Polynesians to Europeans, and many weeds are recent introductions.

Wherever people go they bring weeds with them – on their clothes, and in their equipment, and now more people are moving weeds to Norfolk Island all the time.

The weeds smother and out-compete the native plants, and once the vegetation goes, endemic plants as well as habitat for indigenous wildlife can be lost.

Marco said that Norfolk Island has many endemic species and conservation of this flora is a high priority.

“The local agriculture community might want to know it’s there because it’s a very serious weed and outcompetes grass and impacts local animals,” Marco said.

Emily Bay, Norfolk Island

The Norfolk Island pine tree is an iconic species from the island.

Image: Tom Bannigan
© Australian Museum

Keeping digital records

Herbarium collections provide permanent records of plants and where they were growing. They are invaluable resources, physically and electronically, that are available to the community and researchers from around the world. The collections are being imaged and these images and associated data are what the public can use.

In addition to herbarium material, the team also collected tissue samples for DNA extraction and analysis for future projects. All material, including tissue samples, will also be made available to researchers far and wide.

“Digitisation of the herbarium collections and having quick access to these images has helped research enormously. For example, 10 or 15 years ago before digitisation occurred, if I wanted to see a plant from Europe I would have to wait a year or two for it to come here as a loan,” Marco said.

“Someone may be researching any of the species we collected and might want to know where they are growing around the world. They may be working on taxonomy or on how to control a weed and so having this information is beneficial,” said Marco.

Plant specimens collected in presses

Plant specimens collected in presses.

Image: Mel Wong
© Australian Institute of Botanical Science

To view the original article, and to view more Stories from the Garden, please go to: https://www.rbgsyd.nsw.gov.au/stories/2022/researchers-discover-new-plant-species-on-recent-n


We acknowledge the Polynesian/Tupuna/Tipuna who first called Norfolk Island home, whose story is still being written and pieced together. Through our work, we endeavour to add pages to their widely unknown narrative. We honour their connection to this land/whenua and fauna in times gone by and invite them to guide and breathe life back into the treasures which they left for us to uncover and to piece together the story they did not tell.

We extend that acknowledgement to the descendants of the Pitcairn Islanders who still walk this land and whose Polynesian ties link them back to the East of this Great Ocean – Tahiti. We honour their Pacific story on this land, we acknowledge their Tupuna/Tipuna ancestors and the culture they forged here on Norfolk Island. A culture that continues to thrive today.

And finally, we acknowledge the other Pacific Island communities that now call this Island home. The Pacific diasporas from across the Great Ocean – whose connection to this land may be more recent but whose presence also adds to the Pacific narrative of Norfolk Island in the here and now.