Classification
Class
Magnoliopsida Brongn.
Order
Asterales Link
Family
Compositae Giseke
Genus
Cotula L.
 Nomenclature
Scientific Name:
Cotula coronopifolia L., Sp. Pl. 892 (1753)
Synonymy:
  • = Cotula integrifolia Hook.f., Bot. Antarct. Voy. III. (Fl. Tasman.) Part I, 192, t. 50B (1856)
Vernacular Name(s):
Bachelor's buttons; Waterbuttons; yellow buttons
 Description

Ascending to erect, fleshy, glabrous annual or short-lived perennial up to 30 cm tall. Stems terete, branched from base and above, up to 25–(40) cm long, rooting freely from lower nodes. Lvs fleshy, alternate, apetiolate, linear, lanceolate or spathulate, entire, with few irregular large lobes, or shallowly 1–(2)-pinnatisect, usually perfoliate, rarely amplexicaul, (10)–15–80 mm long; lvs above becoming shorter, more triangular, less often divided and more often amplexicaul. Involucral bracts in 2–3 rows, 4–6 mm long. Capitula solitary, bright yellow, (6)–8–10–(13) mm diam.; peduncles scarcely expanded at apex, solid, 2–7 cm long, c. 1 mm diam.; ♀ florets in 1 or < 1 row, pedicellate, with a corolla; ☿ florets numerous, subsessile, with flattened tubular corolla. Achenes all flattened, hairy on inner surface, glabrous on outer. Achenes of ♀ florets 1.5–2 × 1–1.2 mm; lateral angles with thick, corky, entire, marginal wings. Achenes of ☿ florets 1.1–1.2 × 0.5–0.6 mm; lateral angles thinly ribbed.

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

 Biostatus
Indigenous (Non-endemic)
 Phenology

Flowering: Jan.–Dec.

 Bibliography
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. 1855–1857 ("1860"): 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. III. Flora Tasmaniae. Vol. I. Dicoteledones. Lovell Reeve, London.
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.