Senecio glomeratus subsp. glomeratus
Common name
fireweed
Synonyms
Erechtites glomerata DC. nom. illegit., Senecio argutus A.Rich. nom. illegit., Erechtites arguta (A.Rich) DC., Erechtites quadridentata var. traversii Allan
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.
SENGLO
Chromosome number
2n = 60
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.
2012 | Not Threatened
Previous conservation statuses
2009 | Not Threatened
2004 | Not Threatened
Distribution
Indigenous. Three Kings, North, South, Stewart and Chatham Islands. Present in Australia
Habitat
A weedy species of disturbed ground. Predominantly coastal and lowland but does extend to the subalpine zone. Tolerant of water logged and very dry habitats
Features
Annual to short-lived perennial herb to 2 m tall. Stems erect or ascending to erect, moderately coarse-hairy, becoming sparsely coarse-hairy and/or appressed cottony or nearly glabrous upwards. Mid stem leaves more or less evenly spaced and sized, 50-200 mm long, dark glaucous green to dark green, elliptic to narrow-elliptic, length:width (l:w) ratio 2-7, coarse-dentate to deeply lobate, rarely not dissected, semiamplexicaul; margin with scattered or frequent denticulations or teeth; both surfaces usually coarse-hairy but commonly coarse hairs sparse or absent above mid stem; lower surface green or purple, above mid stem appressed, woolly, cobwebby or more or less glabrous. Uppermost leaves narrow-elliptic, lanceolate or linear, l:w ratio 3-10; dentate or margin appearing entire due to rolling. Unit Inflorescences of many capitula; total number of capitula per stem often 50-300, over topping variable; mature lateral peduncles mostly 4-13 mm long. Calycular bracteoles of capitula 6-12, 1.0-3.0 mm long; peduncle and margin of bracteoles cobwebby to densely woolly at anthesis; involucre 3.0-6.0 x 1.5-2.5 mm; involucral bracts 12-14, glabrous or basally slightly cobwebby, apex erect; stereomes (on drying) gently to moderately convex, green, black at apex, sometimes with a purple zone 1 mm long immediately below tip, sometimes entirely purple. Florets 26-50, c.80% female, dark sulphur yellow; corolla-lobes deltoid, thickened apically; corolla of bisexual florets 3.5-6.5 mm long, 5-lobed; corolla-lobes of female florets 2-4, mostly 0.2-0.3 mm long; corolla-limb commonly deeper cleft on inner face. Cypsela narrow obloid to narrow-ellipsoid, sometimes slightly clavate, < 1/3 of involucral bract length (1.0-1.7 mm long), commonly all medium to dark red-brown, with papillose hairs in lines or narrow bands, l:w ratio of hairs 3; pappus usually > 5 mm long.
Similar taxa
A distinctive and well marked species not easily confused with any other Senecio species present in New Zealand. The dark glaucous-green, elliptic, usually deeply toothed leaves with often dark purple undersides, distinctive coarse to cobwebbed hairs, and dark sulphur yellow florets serve to distinguish it. This species hybridises with S. hispidulus and S. quadridentatus.
Flowering
Throughout the year but most plants peak in summer
Flower colours
Yellow
Fruiting
Late summer to early winter but can present all year
Propagation technique
Easy from fresh seed. Can become invasive
Etymology
senecio: From the Latin senex ‘old man’ (probably referring to the bearded seeds)
Where To Buy
Not commercially available.
Taxonomic Notes
Rather variable, and in Australia two subspecies (subsp. glomeratus and subsp. longifructus) are now recognised. Chatham Island plants differ consistently from mainland specimens in having less divided often broader leaves and shorter capitula. They warrant further study.
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 glomeratus subsp. glomeratus Fact Sheet (content continuously updated). New Zealand Plant Conservation Network. https://www.nzpcn.org.nz/flora/species/senecio-glomeratus-subsp-glomeratus/ (Date website was queried)