Aotearoa New Zealand is a hot spot for forget-me-nots (genus Myosotis), with about 50 species found here and nowhere else. Te Papa Botany Curator Heidi Meudt teamed up with botanist Jessie Prebble from Manaaki Whenua, and Massey University scientists Jennifer Tate, Sofie Pearson, and Weixuan Ning to generate and analyse quite a bit of new genetic data to study the taxonomy and relationships of endemic forget-me-nots. Their new paper paints a complex yet compelling picture of how these species have evolved and radiated throughout the mountains of Aotearoa New Zealand, and makes an important contribution to their taxonomic revision.
What are forget-me-nots?
Forget-me-nots (genus Myosotis) are flowering plants in the family Boraginaceae that are found throughout most temperate areas of the world. About half of the 100 species are found in the northern hemisphere, and the other half in the southern hemisphere, with Aotearoa New Zealand one of the world’s forget-me-not hot spots. A large percentage of our endemic species are considered to be Threatened or At Risk – Naturally Uncommon, which makes them a big conservation priority.
But it order to conserve them, we need to know some information about their taxonomy, classification and relationships. That is, how many species are there? What are their correct names? Where are they found? How can they be identified and distinguished from other species? How are they genetically related to one another? Since 2010, Te Papa Botany Curator Heidi Meudt and her colleagues have been researching and publishing on forget-me-nots using data from DNA, morphology and pollen to answer these questions.
Forget-me-not phylogenomics
This new open access paper is the first phylogenomic analyses of southern hemisphere forget-me-nots. In it, the authors compare three comprehensive genome skim and target-capture DNA datasets for 250-300 individuals of nearly all species of Myosotis native to New Zealand and Australia.
This massive amount of genetic data was generated by Sofie Pearson (now a postdoc at the University of Queensland) from field samples collected by Heidi and Jessie Prebble (Manaaki Whenua) in Jen Tate’s lab at Massey University, and then analysed bioinformatically by Sofie, Weixuan Ning (now a postdoc at Iowa State University), and Jessie Prebble (Manaaki Whenua).
From field work to paper publication, completing this research spanned years of collaborative work, which even became an international project as Sofie and Weixuan moved on to postdoctoral positions overseas.
Relationship status? It’s complicated
Comparison of the different genetic datasets in this paper improved our understanding of the New Zealand species of forget-me-nots and their relationships to one another. The analyses were more informative than previous DNA studies where genetic variation was too low to make inferences about relationships. But like many relationships, well, it’s complicated.
Here are some of the take home messages from the new paper:
- The data showed a mixture of taxonomic and geographic structure within and between species. Having a thorough understanding of the biology and morphology of the species was critical for interpreting the results.
- There have been multiple switches between the two main types of inflorescences (arrangement of flowers) in Myosotis. Whether the plant is ebracteate erect or bracteate prostrate (see images above) is useful for helping to identify species.
- Myosotis species have expanded from the South Island to other areas, including North Island, Stewart Island, subantarctic islands, and Australia.
So much data…
For a paper with so much data, it’s important to openly archive the data so they can be queried, checked, re-used and included in future studies. So, you can find all the scripts, DNA sequences and sequencing reads, DNA sequence alignments, voucher specimens online. In addition, supplementary files associated with the paper detail what these data mean for each of the sampled species regarding species limits, taxonomy and relationships.
Heidi and her colleagues are indebted to the team at New Zealand eScience Infrastructure (NeSI) for use of their computing cloud to analyse the data and for their support, and also thank many others listed in the acknowledgments of the paper.
References cited
Meudt, Heidi M., Sofie M. Pearson, Weixuan Ning, Jessica M. Prebble, and Jennifer A. Tate. 2025. Forget-me-not phylogenomics: Improving the resolution and taxonomy of a rapid island and mountain radiation in Aotearoa New Zealand (Myosotis; Boraginaceae). Molecular Phylogenetics and Evolution: 108250. https://doi.org/10.1016/j.ympev.2024.108250
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Thank you so much, Alastair, this means a lot coming from you, another forget-me-not researcher! For years I have been wanting to make a plate of all of the species and finally I did it 🙂 Thanks for taking the time to comment, we are really grateful for your enthusiastic support.
Wonderful work! Great to see the huge progress you have all made on this. I thoroughly enjoyed reading the published paper and this blog. And, your multispecies plate makes it clear why this group was so attractive to a pollination biologist like myself all those years ago!