The New Zealand Plant Conservation Network

Species

Senecio scaberulus

Etymology

Senecio: From the Latin senex 'old man' (probably referring to the bearded seeds)
scaberulus: a little roughened

Common Name(s)

fireweed

Current Conservation Status

2012 - Threatened - Nationally Critical

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

2009 - Threatened - Nationally Critical
2004 - Threatened - Nationally Endangered

Qualifiers

2012 - EF
2009 - EF

Authority

Senecio scaberulus (Hook.f.) D.G.Drury

Family

Asteraceae

Flora Category

Vascular - Native

NVS Species Code

SENSCA

Structural Class

Dicotyledonous Herbs - Composites

Synonyms

Erechtites scaberulus Hook.f. var. scaberulus, E. scaberulus var. chathamica Allan, Senecio hispidulus var. scaberulus (Hook.f.) Belcher, Senecio hispidulus A.Cunn. nom. illegit.

Distribution

Endemic. New Zealand, North Island from the Three Kings Islands south to Raglan Harbour and the Purua River, north of Thames. S. scaberulus is now mainly seen in eastern Northland and on some of the Hauraki Gulf Islands (Fanal, Ponui and Goat Islands). Also known from Chatham (Rekohu) Island where it was last seen in February 1996. Recorded from the South Island from Picton, Akaroa and Dunedin. All these port records (which include the type gathering) are possibly accidental introductions from the North Island via shipping traffic as this species was once abundant on the Auckland waterfront. Senecio scaberulus has not been reliably recorded from the South Island since the 1860s.

Habitat

Coastal scrub, forest margins and clearings. Shaded sites amongst short grasses, under coastal pohutukawa (Metrosideros excelsa Sol. ex Gaertn.) forest or short scrub, on rock outcrops, cliffs or banks near the sea, often occurring with Senecio hispidulus A.Rich. Also found at inland sites, on bare lava, with forest on bluffs and in canopy gaps.

Features

Grey-green to silvery grey-green, annual or short-lived perennial herb up to 1.5 m tall (usually much less, and depending on local growing conditions). All vegetative parts densely covered in short hairs of both the velutinous and hispid type. Mid cauline leaves 30-200 x 0.5-6 mm, upper surface dark grey-green, covered in distinctly shorter more hispid hairs, undersides pale grey to purple, densely invested in longer, velutinous hairs. Lamina initially sessile becoming shortly petiolate further up stem; lamina narrowly to broadly ovate-elliptic, dentate, pinnately lobed, or pinnatifid, with segments triangular to narrow-oblong, or 1-3-pinnatifid at base. Uppermost leaves similar but smaller, lanceolate, dentate, lobed or sometimes entire. Inflorescences 1-3 per plant, either in sparse or densely flowered corymbs depending on growing conditions, glabrescent. Supplementary bracts 4-8, 1-2 mm long. Involucral bracts 10-13, glabrescent or glabrous, 5-7 mm long. Ray florets absent. Disc sulphur yellow, 2-3 mm diam. Cypsela (seed) 2-3 mm long, subcylindric, slightly constricted below apex, deeply and longitudinally ribbed, surface more or less evenly covered in short hispid hairs.

Similar Taxa

Senecio hispidulus A.Rich. is similar but usually larger, and its more heavily divided leaves are covered with short white hairs that have a rasp-like rather than velvety texture when brushed. It also has a more crowded inflorescence and slightly smaller cypsela (seeds) which only have hairs in distinct rows rather than scattered over the seed surface. S. scaberulus might also be confused with S. glomeratus Poiret, but that species is copiously covered in long white, cob-webbed (lanate) hairs.

Flowering

October-February

Flower Colours

Yellow

Fruiting

November - April

Propagation Technique

Easy from fresh seed. Does best in a free draining semi-shaded site with minimal competition from taller plants. Rather fast growing. However, this is a weedy species which is unlikely to prove popular in cultivation.

Threats

This species is seriously threatened throughout its range. Formerly widespread in open successional habitats, especially the Auckland lava fields, these habitats have either been lost to urbanisation or covered in foreign weed species. Browsing by domestic stock, feral mammals and exotic invertebrate herbivores appears to be a problem in some areas. At all of the known sites the species is still subjected to competition from exotic plants. Hybridization with Senecio hispidulus is also believed to be a serious threat to this species.

Chromosome No.

2n = 60

Endemic Taxon

Yes

Endemic Genus

No

Endemic Family

No

 

 

  

Attribution

Fact Sheet prepared for the NZPCN by P.J. de Lange 12 July 2005. Description by P.J. de Lange and subsequently published in de Lange et al. (2010).

References and further reading

de Lange, P.J.; Heenan, P.B.; Norton, D.A.; Rolfe, J.R.; Sawyer, J.W.D. 2010: Threatened Plants of New Zealand. Canterbury University Press, Christchurch.

This page last updated on 19 Dec 2014