The New Zealand Plant Conservation Network

Species

Senecio biserratus

Etymology

Senecio: From the Latin senex 'old man' (probably referring to the bearded seeds)
biserratus: doubly-toothed

Current Conservation Status

2018 - At Risk - Declining

Conservation status of New Zealand indigenous vascular plants, 2012
The conservation status of all known New Zealand vascular plant taxa at the rank of species and below were reassessed in 2012 using the New Zealand Threat Classification System (NZTCS). This report includes a statistical summary and brief notes on changes since 2009 and replaces all previous NZTCS lists for vascular plants. Authors: Peter J. de Lange, Jeremy R. Rolfe, Paul D. Champion, Shannel P. Courtney, Peter B. Heenan, John W. Barkla, Ewen K. Cameron, David A. Norton and Rodney A. Hitchmough. File size: 792KB

Previous Conservation Status

2012 - Not Threatened
2009 - Not Threatened
2004 - Not Threatened

Authority

Senecio biserratus Belcher

Family

Asteraceae

Flora Category

Vascular - Native

NVS Species Code

SENBIS

Structural Class

Dicotyledonous Herbs - Composites

Synonyms

Senecio flaccidus A.Rich. nom. illegit., Erechtites sonchoides DC.

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.

Chromosome No.

2n = c.96, 100

Endemic Taxon

No

Endemic Genus

No

Endemic Family

No

This page last updated on 29 Aug 2016