Classification
 Nomenclature
Scientific Name:
Jacobaea vulgaris Gaertn., Fruct. Sem. Pl. 2, 445, t. 170 (1791)
Synonymy:
  • = Senecio jacobaea L., Sp. Pl. 870 (1753)
 Description

Erect biennial or perennial herb, 30–120 cm tall. Stems densely lanate above but soon glabrous, usually branched only above, sometimes branched from base. Basal lvs lanate when young, usually becoming almost glabrous but often remaining hairy on veins of lower surface, rarely sparsely to moderately hairy on both surfaces, petiolate; petiole < lamina, amplexicaul; lamina lyrate-pinnatifid, obovate to ovate-oblong, obtuse to subacute at apex, (3)–5–20–(25) × (2)–4–6–(8) cm; segments ovate, oblong, or obovate, 1–2-pinnatisect; venation pinnate. Cauline lvs lyrate-pinnatifid to 1-pinnate; segments again 1–2-pinnatisect; uppermost lvs apetiolate, with narrow segments. Capitula usually numerous in dense, flat-topped corymbs, rarely fewer and more diffuse. Supplementary bracts 3–10, lanceolate, 1.5–3 mm long. Involucral bracts 11–14, ovate-oblong, 3–5 mm long, usually glabrous, sometimes with a few scattered hairs. Ray florets 11–13; ligules bright yellow, 5–12 mm long. Disc golden yellow. Achenes terete, 1.4–2.5 mm long, those of ray florets glabrous, those of disc florets moderately hairy; pappus 3.5–5 mm long, soon deciduous from ray achenes.

[From: Webb et al. (1985) Flora of New Zealand. Volume 4 as Senecio jacobaea L.]

 Biostatus
Exotic
 Bibliography
Biosecurity New Zealand 2012: Regional Pest Management Strategies Database. http://www.biosecurityperformance.maf.govt.nz/
Connor, H.E. 1977: The Poisonous Plants in New Zealand. Edition 2. Government Printer, Wellington. [as Senecio jacobaea L.]
Gaertner, J. 1790–1792: De Fructibus et Seminibus Plantarum. Vol. 2. Stuttgart.
Howell, C. 2008: Consolidated list of environmental weeds in New Zealand. DOC Research & Development Series 292: 42. [as Senecio jacobaea L.]
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.
Pelser, P.B.; Veldkamp, J.-F.; Meijden van der, P. 2006: New combinations in Jacobaea Mill. (Asteraceae - Senecioneae). Compositae Newsletter 44: 1–11.