Leptinella tenella
Biostatus
Native – Endemic taxon
Category
Vascular
Structural class
Herbs - Dicotyledonous composites
Flower colours
Green, Yellow
Detailed description
Soft, widely creeping, monoecious perennial herb forming loose patches or a dense turf depending on local conditions. Rhizomes at or near soil surface, dark red-green or green, pliant, sparsely villous hairy, branches usually single at flowering nodes; leaves in two rows single at apex, 5–20 mm apart. Short shoots alternate on either side of rhizome, bearing 1–6–(8) clustered leaves, occasionally converting to rhizomes, then bearing distant leaves. Roots white, numerous, slender up to 0.4 mm diameter. Leaves 1-pinnatifid, 10–40 × 4–15 mm, lamina up to 35 mm long, obovate, membranous, bright green (verdent green), sometimes with proximal pinnae brown pigmented, glabrous; midrib not raised on upper surface; pinnae 6–10–(12) pairs, not or scarcely overlapping, cut deeply to rhachis, broadly elliptic to suborbicular; teeth numerous, on all pinnae, up to 12 per pinna, usually extending around the entire margin (sometimes lacking on proximal side), cut to ⅓ across pinna, narrowly triangular to oblong, acute or mucronate, large ones sometimes bearing 1–2 teeth. Peduncles on rhizomes 5–15 mm, breen or dark red-green, ebracteate or rarely with 1 bract, sparsely pilose. Capitula 2–6 mm diameter; surface convex; involucre upcurved or flat; involucral bracts 8–12 in 2 subequal rows, broadly elliptic, green, glabrous, with broad red-brown, scarious margins, not growing after anthesis; pistillate florets 20–45 in 2 or more rows, c. 1.5 mm long exceeding phyllaries, slightly curved, yellow-green; corolla slightly longer than wide, with almost equal dentation; staminate florets fewer, 10–15. Cypsela up to 1.3 × 0.6 mm, brown, slightly compressed, surface chartaceous and smooth.
Similar taxa
The bright green finely toothed almost feathery leaves are very distinctive. The only other New Zealand Leptinella to present this condition is the Chatham Islands and Auckland Islands endemic L. potentillina F. Muell. which is typically yellow-green rather than bright green and much larger in all respects, and is allopatric from L. tenella. In New Zealand proper L. tenella is most likely to be confused with L. dispersa (D.G.Lloyd) D.G.Lloyd et C.Webb with which it sometimes grows. The best way to distinguish it is by the obvious teeth which run all along the margin of the much larger pinnae and by the numerous female florets which are not obscured by the shorter involucral bracts. In the Wellington region where L. dispersa subsp. dispersa may be monoecious, the floral distinction with L. tenella is less obvious. In these areas the fact that subsp. dispersa leaves are typically brown to purple pigmented toward the base can help distinguish it from L. tenella.
Distribution
Endemic. New Zealand: North Island (scattered from Mt Camel to Kawhia Harbour in the west and Matatā in east, thence absent until the Horowhenua and Wairarapa), South Island (local in North-west Nelson and the Marlborough Sounds).
Habitat
Lowland, usually on stream margins where they enter estuaries, on lake margins or on the margins of freshwater swamps and wetlands bordering saltmarsh. On occasion this species has been found on cattle pugged swampy ground bordering saltmarshes. Intolerant of much shading and grass competition it favours sites that are kept open through periodic disturbance from high tides and flooding. Very rarely found inland on lake margins.
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.
Please note, threat classifications are often suggested by authors when publications fall between NZTCS assessment periods – these interim threat classification statuses has not been assessed by the NZTCS panel.
- 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 Endangered | Qualifiers: Sp, DPR, DPS, DPT, RR
Threats
A naturally uncommon species of sporadic distribution. Some populations have declined due to spread of weeds and associated wetland drainage
Detailed taxonomy
Family
Asteraceae
Synonyms
Soliva tenella A.Cunn., Cotula membranacea D.G.Lloyd
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Ecology
Flowering
August–November–(December)
Fruiting
October–January–(April)
Life cycle and dispersal
Papery cypselae are dispersed by wind and possibly attachment (Thorsen et al., 2009).
Propagation technique
Easy from rooted pieces, a very attractive plant ideal for damp soils. Prefers a sunny aspect but will grow in dappled light. An excellent lawn cover on poorly drained ground.
Wetland plant indicator status rating
Information derived from the revised national wetland plant list prepared to assist councils in delineating and monitoring wetlands (Clarkson et al., 2021 Manaaki Whenua – Landcare Research Contract Report LC3975 for Hawke’s Bay Regional Council). The national plant list categorises plants by the extent to which they are found in wetlands and not ‘drylands’. The indicator status ratings are OBL (obligate wetland), FACW (facultative wetland), FAC (facultative), FACU (facultative upland), and UPL (obligate upland). If you have suggestions for the Wetland Indicator Status Rating, please contact: [Enable JavaScript to view protected content]
FAC: Facultative
Commonly occurs as either a hydrophyte or non-hydrophyte (non-wetlands).
Other information
Cultivation
Occasionally available from specialist native plant nurseries.
Etymology
leptinella: From the Greek word leptos (meaning slender, thin or delicate), referring to the ovary
tenella: Delicate
Chromosome number
2n = 52
Previous conservation statuses
2017 | Threatened – Nationally Vulnerable | Qualifiers: DP, RR, Sp
2012 | At Risk – Declining | Qualifiers: DP, RR, Sp
2009 | At Risk – Declining | Qualifiers: DP, RR, Sp
2004 | Sparse
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 tenella.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Leptinella tenella Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/leptinella-tenella/ (Date website was queried)