2021 Favourite Plant Vote candidate profile - Leptinella serrulata
The 2021 Favourite Native Plant vote will open on 1 October and run for 1 month. In the lead up to the return of this popular vote, NZPCN committee members are profiling some of the plants which they feel need a little more love. For the full article with all the images see issue 210 of Trilepidea.
Favourite plant candidate: Leptinella serrulata, dryland button daisy
Why I have selected this species: To me Leptinella serrulata is a real icon of our eastern South Island dryland ecosystems, although very few kiwis have heard of this special little plant, let alone seen it. It is a very cryptic species; being tiny, prostrate, and well-camouflaged in the naturally grey/brown dryland habitats it occupies. The whakatauki “Ahakoa he iti he pounamu” seems very appropriate for the dryland button daisy, as it means “despite being small you are of great value”. Although it is tiny, I think L. serrulata is a stunning plant—it has attractive mint-green and bronze feathery leaves with fine silvery hairs, and lemon-yellow button flower heads held proudly above the mat-forming rosettes. Although I haven’t had the pleasure of seeing it in full bloom, apparently the flowers “have a sweet honey dew scent.” (The Plant Store 2021).
Distribution: Leptinella serrulata is endemic to New Zealand. It occurs in the South Island east of the main divide, mainly inland from Marlborough (Wairau River), Canterbury, and Otago south to Foveaux Strait (see map taken from iNaturalist NZ 2021). Habitat Leptinella serrulata occurs from sea level to 1500 m a.s.l. It grows in dry, free-draining sites on the Canterbury Plains, along river flats, and in intermontane basins, where it grows in open sites amongst tussock grassland or under kānuka (Kunzea serotina) shrubland. It is more rarely found in coastal sites, where it colonises open sandy ground (Kaitorete Spit and Tiwai Peninsula are important strongholds for the species).
Current population: Leptinella serrulata has scattered, small populations across the eastern South Island. The species is classified as ‘At Risk – Declining’, with the qualifier ‘SP’ or sparse (de Lange et al. 2018), which means that it naturally occurs within typically small and widely scattered sub populations. The species only has 35 observations by 16 people on the iNaturalist website (iNaturalistNZ 2021), which illustrates how few New Zealanders have been lucky enough to see this little gem.
Threats: Leptinella serrulata faces many of the same threats as our other native dryland plant species. Habitat loss, modification, and weed invasion are major causes of population decline, with the primary driver being agricultural intensification (i.e. cultivation, fertilisation, and/or irrigation). Because of its diminutive stature, the species is unable to compete with introduced grasses and herbs such as hawkweeds (Pilosella officinarum and Hieracium spp.). Coastal erosion is also a long-term threat to the populations on the Tiwai Peninsula.
What do we need to do right now? We need to raise awareness about Leptinella serrulata and the special flora (and fauna) of the eastern South Island drylands, and to advocate for better protection and management of these threatened ecosystems. Leptinella serrulata makes an ideal ground cover for sunny, dry/well-drained spots in the garden—why not try planting it at home so you can enjoy looking at this iconic dryland plant every day!
References and further reading:
de Lange P.J., Rolfe J.R., Barkla J.W., Courtney S.P., Champion P.D., Perrie L.R., Beadel S.M., Ford K.A., Breitwieser I., Schonberger I., Hindmarsh-Walls R., Heenan P.B. and Ladley K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series 22. Department of Conservation, Wellington. 82 p.
de Lange P.J. 2021: Leptinella serrulata Fact Sheet. New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/ flora/species/leptinella-serrulata/. Date accessed: 28 August 2021.
iNaturalistNZ 2021: Observations of Leptinella serrulata on the iNaturalist website. https://inaturalist.nz/observations?ver ifiable=true&taxon_id=403374&place_id=6803&preferred_place_id=6803&locale=en.Date accessed: 28 August 2021.
Lloyd D.G. 1972: A revision of the New Zealand, Subantarctic, and South American species of Cotula, section Leptinella. New Zealand Journal of Botany 10: 277–372.
The Plant Store 2021: Leptinella serrulata. https://www.theplantstore.co.nz/products/nz-natives/leptinella-serrulata/. Date accessed: 28 August 2021.
Trees for Canterbury 2021: Creating a lawn alternative with native plants. https://www.treesforcanterbury.org.nz/plantingtrees-and-shrubs/creating-a-lawn-alternative-with-native-plants/. Date accessed: 28 August 2021.
Posted: 1 September 2021