Classification
Class
Magnoliopsida Brongn.
Order
Asterales Link
Family
Compositae Giseke
Genus
Senecio L.
 Nomenclature
Scientific Name:
Senecio wairauensis Belcher, Ann. Missouri Bot. Gard. 43: 55 (1956)
Synonymy:
  • ≡ Erechtites wairauensis (Belcher) Allan, Fl. New Zealand 1, 735 (1961)
  • = Erechtites prenanthoides var. β minor Hook.f., Bot. Antarct. Voy. II. (Fl. Nov.-Zel.) Part I, 141 (1853)
  • = Erechtites glabrescens Kirk, Trans. & Proc. New Zealand Inst. 9: 550 (1877) nom. illeg., non Erechtites glabrescens DC. 1838
  • = Erechtites wairauensis var. robusta Allan, Fl. New Zealand 1, 736 (1961)
Etymology:
The epither wairauensis apparently refers to the type locality (Lake Rotoiti, Nelson); when it was first recorded by T. Kirk the location was recorded as Roto-iti, Wairau Valley, perhaps reflecting the route Kirk took up the Wairau Valley to get to Lake Rotoiti.
Vernacular Name(s):
Fireweed
 Description

Erect annual to short-lived perennial herb. Mid cauline lvs almost glabrous or with few scattered hairs on both surfaces, apetiolate or cuneately narrowed to appear petiolate, narrow-oblong, elliptic, or narrow-obovate, shallowly pinnately lobed and denticulate to lyrate-pinnatifid or 1-pinnatifid with ± oblong, few-toothed (rarely many-toothed) segments, amplexicaul and dentate at base or rarely not amplexicaul, (4)–6–13 × (1)–2–5 cm. Uppermost lvs smaller, often lanceolate, usually 1-pinnatifid, sometimes only dentate or entire. Supplementary bracts 3–6, 1–2 mm long. Involucral bracts (8)–12–13–(14), glabrous, 6–7–(8) mm long. Ray florets 0. Disc yellow, 2–3 mm diam. Achenes subcylindric, narrowed to and constricted below apex, glabrous or with scattered hairs in 1–3 rows in narrow grooves between broad ribs, (2.2)–3–4–(5) mm long.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

 Biostatus
Indigenous (Endemic)
 Phenology

Flowering: Dec.–May.

 Bibliography
Belcher, R.O. 1956: A Revision of the Genus Erechtites (Compositae) with Inquiries into Senecio and Arrhenechthites. Annals of the Missouri Botanical Garden 43: 1–85.
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series. No. 22. [Not Threatened]
de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington. [Not Threatened]
Hooker, J.D. 1852–1853 ("1853"): The Botany of the Antarctic Voyage of H.M. Discovery Ships Erebus and Terror in the Years 1839–1843, under the command of Captain Sir James Clark Ross. II. Flora Novae-Zelandiae. Part I. Flowering plants. Lovell Reeve, London.
Kirk, T. 1877: Descriptions of new plants. Transactions and Proceedings of the New Zealand Institute 9: 547–552.