Senecio biserratus
Synonyms
Senecio flaccidus A.Rich. nom. illegit., Erechtites sonchoides DC.
Family
Asteraceae
Flora category
Vascular – Native
Endemic taxon
No
Endemic genus
No
Endemic family
No
Structural class
Herbs - Dicotyledonous composites
NVS code
The National Vegetation Survey (NVS) Databank is a physical archive and electronic databank containing records of over 94,000 vegetation survey plots - including data from over 19,000 permanent plots. NVS maintains a standard set of species code abbreviations that correspond to standard scientific plant names from the Ngä Tipu o Aotearoa - New Zealand Plants database.
SENBIS
Chromosome number
2n = c.96, 100
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 | At Risk – Declining
Previous conservation statuses
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous. North, South and Stewart Islands. Present also in Australia
Habitat
Coastal and lowland habitats, in early successional habitats. This species is often associated with dune systems where it usually grows amongst Muehlenbeckia complexa (A.Cunn.) Meisn.
Features
Annual to short-lived subsucculent perennial herb up to 1 m tall but usually much less. Stems erect, basally sparsely or sometimes moderately coarse-hairy; indumentum reducing upwards. Mid stem leaves more or less evenly spaced and sized, 50-150 mm long, length:width ratio 1.5-4, dark green to yellow green, elliptic to narrow-elliptic or lanceolate, coarse-dentate to deeply lobate; segments 3-9 per side extending along much of length, tending to be larger in proximal two-thirds, antrorse, deltoid to near oblong; base usually auriculate, with auricles divided, semiamplexicaul; margin serrulate or denticulate, with denticulations frequent; both surfaces glabrous or sparsely hispid to scabridulous, rarely coarse-hairy; lower surface pale green to purple, more or less glabrous except on veins. Uppermost Leaves similar, l:w ratio 3-6, sometimes widest at auricles. Unit Inflorescences of many capitula; total number of capitula per stem often 50-200; not overtopping or only moderate; mature lateral peduncles mostly 5-10 mm long. Calycular bracteoles 3-6, 1.0-2.0 mm long; peduncle and margin of bracteoles more or less glabrous at anthesis; involucre 4.5-7.5 x 1.0-1.5 mm; involucral bracts predominantly 7-10, glabrous, apex erect; stereomes of dry material flat to slightly convex, thin, green, minutely purpled at apex. Florets 12-20, pale yellow, c.70% female; corolla-lobes nearly oblong, thickened apically; corolla of bisexual florets 4.5-6.0 mm long, 4-5-lobed; corolla-lobes of female florets 3-4, 0.2-0.3 mm long. Cypsela 2.0-3.2 mm long, dark brown, narrow oblong to oblong-ellipsoid, with papillose hairs in dense bands, l:w ratio of hairs 3. Pappus 5-6 mm long.
Similar taxa
Distinguished from the other indigenous disciform Senecio by the subsucculent, dark green glabrate leaves; pinnately lobed mid stem leaves, whose segments are irregularly serrate to dentate and by the cypsela (seeds) which are between 2-3 mm long (range mainly 2.5-2.8 mm long). Senecio biserratus is the only indigenous disciform senecio to frequent sand dune country.
Flowering
August - January
Flower colours
Yellow
Fruiting
September - May
Propagation technique
Easy from fresh seed and can become invasive.
Threats
Not threatened - however it has declined from large parts of the northern part of its range.
Etymology
senecio: From the Latin senex ‘old man’ (probably referring to the bearded seeds)
biserratus: Doubly-toothed
Where To Buy
Not commercially available
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (12 July 2005). Description based on Thompson (2004).
References and further reading
Thompson, I.R. 2004: Taxonomic studies of Australian Senecio (Asteraceae): 1. The disciform species. Muelleria 19: 101-214.
NZPCN Fact Sheet citation
Please cite as: de Lange, P.J. (Year at time of access): Senecio biserratus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/senecio-biserratus/ (Date website was queried)