Leptinella rotundata
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledonous composites
Flower colours
Brown, Green
Detailed description
Creeping perennial herb forming diffuse patches. Rhizomes on soil surface, dark green or purple-green, sparsely covered in long, silky hairs; branches few, occurring at flowering nodes; leaves paired, spaced 10–30 mm apart; short shoots alternating on both sides of rhizome, these with 3-4 leaves. Leaves simple 10–50 × 5–15 mm, suborbicular, membranous, yellow-green, sometimes purple-brown pigmented toward leaf base, both surfaces sparsely covered in long silky hairs, veins not evident. Leaf margins crenate. Flowers monoecious, yellow-green, arising directly from rhizomes on stout, villous peduncles 20–60 mm long. Capitula 5–7 mm diam., hemispherical, with 6–12 phyllaries (bracts) in 1–2 subequal rows, broadly elliptic, green, villous, with a distinct, sometimes finely toothed brown pigmented margin. Pistillate (female) florets usually 0–5, sometimes up to 12 in 1 incomplete row. Staminate (male) flowers 40–90. Achenes (seeds) 1.9 x 1.1 mm, brown.
Similar taxa
Easily distinguished from other Leptinella species by the suborbicular leaves and high chromosome number. Lloyd (1972) indicates that the reproductive system, coupled with the high chromosome number and northern distribution, are unusual traits in Section Elongata, within which this species belongs, and infers from that that L. rotundata is potentially a relic species within this section.
Distribution
Endemic. New Zealand: North Island (west coast from Scott’s Point, Te Paki south to the Waitakere Ranges).
This species should be looked for in any suitable cliffside habitat along the west coast of the northern North Island. In some respects it has a distribution similar to another west coast endemic Veronica speciosa, which has been recorded at three of the five known sites for L. rotundata. The species was rediscovered in the Waitakere Ranges in April 2010 some 113 years after it was first found there by Thomas Cheeseman and 104 years after it was described by him as new to science from those gatherings.
Habitat
Coastal cliff faces and boulder falls. Occupies a very specific habitat, i.e. preferring the wind and salt-blasted margins of vegetated cliff faces, where other competing plants are held in check. Typically sparse and patchy in its distribution at any given site.
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2023 | Threatened – Nationally Critical | Qualifiers: Sp, DPS, DPT, RF
Threats
This species is threatened at all known locations by coastal erosion, weed invasion of its narrow cliff-top and boulder bank habitats, and by the seemingly natural separation of male and female plants. Thus in the wild, as far as is known, seed is rarely if ever formed. The separation of the sexes is not unique to this species in the genus, being also the case for Leptinella dispersa subsp. rupestris (D.G.Lloyd) D.G.Lloyd et C.Webb.
Detailed taxonomy
Family
Synonyms
Cotula dioica var. rotundata Cheeseman, Cotula rotundata (Cheeseman) D.G.Lloyd
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
August–January (but sporadic flowering can occur at any time of the year)
Fruiting
October–April (but fruiting material can be found at any time of the year)
Life cycle and dispersal
Papery cypselae are dispersed by wind and possibly attachment (Thorsen et al., 2009).
Propagation technique
Very easily grown by division of established plants. In the wild female plants occur in isolation from “males” so seed set is minimal, and restriction to hermaphroditic flowers on “male” plants. For this reason most plants in cultivation are raised from division of larger individuals. In cultivation this species is often short-lived and benefits from regular division to keep plants vigorous.
Other information
Etymology
leptinella: From the Greek word leptos (meaning slender, thin or delicate), referring to the ovary
Chromosome number
2n = c.312
Previous conservation statuses
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2022-2023 using the New Zealand Threat Classification System (NZTCS) – more information about this can be found on the NZTCS website. This report includes replaces all previous NZTCS lists for vascular plants. Previous assessments can be found here.
- Conservation status of vascular plants in Aotearoa New Zealand, 2023. 2024. Peter J. de Lange, Jane Gosden, Shannel P. Courtney, Alexander J. Fergus, John W. Barkla, Sarah M. Beadel, Paul D. Champion, Rowan Hindmarsh-Walls, Troy Makan and Pascale Michel Department of Conservation. Source: NZTCS and licensed by DOC for reuse under the Creative Commons Attribution 4.0 International licence.
2017 | Threatened – Nationally Endangered | Qualifiers: DP, RR, Sp, St
2012 | Threatened – Nationally Vulnerable | Qualifiers: St
2009 | Threatened – Nationally Critical | Qualifiers: DP, Sp
2004 | Threatened – Nationally Vulnerable
Referencing and citations
References and further reading
Lloyd DG. 1972. A revision of the New Zealand, Subantarctic, and South American species of Cotula, section Leptinella. New Zealand Journal of Botany 10(2): 277–372. https://doi.org/10.1080/0028825X.1972.10429156.
Thorsen MJ, Dickinson KJM, Seddon PJ. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285–309. https://doi.org/10.1016/j.ppees.2009.06.001.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (31 August 2006). Description from Lloyd (1972) - as Cotula rotundata.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Leptinella rotundata Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/leptinella-rotundata/ (Date website was queried)