Senecio hispidulus
Common names
fireweed
Biostatus
Native
Category
Vascular
Structural class
Herbs - Dicotyledonous composites
Flower colours
Yellow
Detailed description
Annual to short-lived perennial herb up to 2 m tall. Stems erect, sparsely to moderately coarse-hairy or glabrous near base, if hairy reducing to more or less glabrous above mid stem. Mid stem leaves more or less evenly spaced and sized, 70-150 mm long, dark green to yellow green, sometimes tinged with red, narrow-ovate to lanceolate, rarely narrow-elliptic or linear, length:width (l:w) ratio 2.5-6, usually coarse-dentate to sub-pinnatisect; segments 2-5 per side predominantly in proximal two-thirds, large divisions usually in proximal half, slightly antrorse, deltoid to narrow-deltoid or occasionally sub-oblong; base auriculate with auricles divided, semiamplexicaul; margins with scattered denticulations or teeth; both surfaces coarse hairy; lower surface dark green or purple, often with weakly cobwebby hairs overlaying coarse-hairs. Uppermost leaves narrow-lanceolate or linear, l:w 5-15 (excluding auricles), lobate or appearing undissected due to rolling of lamina, often widest at auricles. Unit Inflorescence usually of many capitula; total number of capitula per stem often 50-100; overtopping marked; mature lateral peduncles mostly 7-14 mm long. Calycular bracteoles of capitula 3-6, 1.0-2.5 mm long; peduncle and margin of bracteoles more or less glabrous at anthesis; involucre 4.5-6.0 x 1.4-1.8 mm, involucral bracts 9-13, glabrous, with erect apex; stereomes of dried material moderately convex, green with minutely blackened tip. Florets 18-35, pale yellow to yellow, c.70% female; corolla-lobes deltoid, thickened apically; corolla of bisexual florets 4.5-6.0 mm long, 5-lobed; corolla-lobes of female florets 4, 0.3-0.5 mm long. Cypsela 1.5-2.2 mm long, red-brown, narrow-obloid with fine papillose hairs in lines or narrow bands, l:w ratio of hairs 3. Pappus 4-6 mm long.
Similar taxa
Most frequently confused with the Acutely Threatened Senecio scaberulus. From that species it differs by its coarsely hispid, dark green rather than grey-green velutinous leaves, taller size (up to 2 m cf. 1 m in S. scaberulus) and by the cypsela which have hairs aligned longtidinally in the grooves rather than scatetred over the entire surface. The hybrid S. hispidulus x S. scaberulus is common in some locations where S. scaberulus was formerly present.
Distribution
Indigenous. Three Kings, North, South, Stewart and Chatham Islands. Present in Australia.
Habitat
Coastal to montane. Widespread in disturbed habitats, especially in places recently burned or cleared of indigenous vegetation. Often found as a pasture weed, and can be common in urban areas. This species was regarded as scarce in the South Island during the 1800s. It is now common in the northern two-thirds of that island though still local in the west and it is still spreading south. It seems to be a recent arrival on the Chatham Islands.
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.
- 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 | Not Threatened | Qualifiers: SO
Detailed taxonomy
Family
Synonyms
Erechtites hispidula (A.Rich.) DC.
Taxonomic notes
In New Zealand two forms are present. One, represented by the oldest collections is distinctively covered in short, hispid hairs along the stems, the other is quite glabrous. The glabrous form first appeared in Northland during the late 1800s. Both forms merge in Australia.
Endemic taxon
No
Endemic genus
No
Endemic family
No
Ecology
Flowering
August - May
Fruiting
September - July
Propagation technique
Easily grown from fresh seed. very weedy and invasive.
Other information
Etymology
senecio: From the Latin senex ‘old man’ (probably referring to the bearded seeds)
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.
SENHIS
Chromosome number
2n = 60
Previous conservation statuses
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.
- 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.
2017 | Not Threatened | Qualifiers: SO
2012 | Not Threatened
2009 | Not Threatened
2004 | Not Threatened
Referencing and citations
References and further reading
Thompson, I.R. 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 hispidulus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/senecio-hispidulus/ (Date website was queried)