Leptinella tenella
Synonyms
Soliva tenella A.Cunn., Cotula membranacea D.G.Lloyd
Family
Asteraceae
Flora category
Vascular – Native
Endemic taxon
Yes
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledonous composites
Chromosome number
2n = 52
Current conservation status
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2017 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2012 and replaces all previous NZTCS lists for vascular plants. Authors: By Peter J. de Lange, Jeremy R. Rolfe, John W. Barkla, Shannel P. Courtney, Paul D. Champion, Leon R. Perrie, Sarah M. Beadel, Kerry A. Ford, Ilse Breitwieser, Ines Schönberger, Rowan Hindmarsh-Walls, Peter B. Heenan and Kate Ladley.
2018 | Threatened – Nationally Vulnerable
Previous conservation statuses
2012 | At Risk – Declining | Qualifiers: DP, RR, Sp
2009 | At Risk – Declining | Qualifiers: DP, RR, Sp
2004 | Sparse
Distribution
Endemic. North Island, northern South Island. In the North Island scattered from Mt Camel to Kawhia Harbour in the west and Matata in east, thence absent until the Horowhenua and Wairarapa. 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.
Features
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 x 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 1/3 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 x 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 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.
Flowering
August - November (-December)
Flower colours
Green, Yellow
Fruiting
October - January (-April)
Life cycle
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.
Threats
A naturally uncommon species of sporadic distribution. Some populations have declined due to spread of weeds and associated wetland drainage
Etymology
leptinella: From the Greek word leptos (meaning slender, thin or delicate), referring to the ovary
tenella: Delicate
Where To Buy
Occasionally available from specialist native plant nurseries
Cultural Use/Importance
In the Wellington region where L. dispersa subsp. dispersa may be monoecious so 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
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange 31 August 2006. Description from Lloyd (1972) - as Cotula tenella.
References and further reading
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.
Thorsen, M. J.; Dickinson, K. J. M.; Seddon, P. J. 2009. Seed dispersal systems in the New Zealand flora. Perspectives in Plant Ecology, Evolution and Systematics 11: 285-309
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)