Senecio biserratus
Biostatus
Native
Category
Vascular
Structural class
Herbs - Dicotyledonous composites
Flower colours
Yellow
Detailed description
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, width:length 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 ⅔, 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, width:length ratio 1-2, 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 × 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, width:length ratio of hairs 1–3. 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 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.
Distribution
Indigenous. New Zealand: North Island, South Island and Stewart Island/Rakiura. 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.
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 | At Risk – Declining | Qualifiers: SO
Threats
Declining throughout much of its range and in the northern South Island now present only on offshore islands. Reasons for the delcine are unclear.
Detailed taxonomy
Family
Asteraceae
Synonyms
Senecio flaccidus A.Rich. nom. illegit., Erechtites sonchoides DC.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
August–January
Fruiting
September–May
Propagation technique
Easy from fresh seed and can become invasive.
Other information
Where To Buy
Not commercially available
Etymology
senecio: From the Latin senex ‘old man’ (probably referring to the bearded seeds)
biserratus: Doubly-toothed
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
Previous conservation statuses
2017 | At Risk – Declining | Qualifiers: DP, SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Thompson IR. 2004. Taxonomic studies of Australian Senecio (Asteraceae): 1. The disciform species. Muelleria 19: 101–214.
Attribution
Fact sheet prepared for NZPCN by P.J. de Lange (12 July 2005). Description based on Thompson (2004).
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)