Cotula

Brass buttons Cotula coronopifolia, copyright Franco Folini.

Belongs within: Anthemideae.

Cotula, buttonweeds, is a mostly Southern Hemisphere genus of composite herbs bearing solitary flower heads that usually lack ray florets on terminal peduncles.

Characters (from Black & Robertson 1965): Small herbs with alternate leaves; heads small, with all flowers of equal length, solitary on rather long terminal peduncles. Involucre hemispherical, bracts nearly equal with scarious margins, in about two rows; receptacle naked; outer flowers female or bisexual, fertile, usually without corollas; disk-flowers numerous, tubular, four-toothed, bisexual and sterile or fertile; achenes very small (rarely over one millimetre long), more or less compressed, smooth or almost so; pappus absent.

<==Cotula Linnaeus 1753 A61
    |  i. s.: C. bipinnata BR65
    |         C. cotuloides GK00
    |         C. filifolia BR65
    |         C. hemisphaerica VB02
    |         C. monticola Simpson 1952 (n. d.) A61
    |         C. reptans BR65
    |         C. scariosa D03
    |         C. turbinata GK00
    |         C. vulgaris Levyns 1941 [incl. C. filifolia var. decumbens] BR65
    |--C. (subg. Cotula) coronopifolia Linnaeus 1753 A61 (see below for synonymy)
    `--C. (subg. Strongylosperma) australis (Sieb. ex Spreng.) Hooker 1853 (see below for synonymy) A61

Cotula australis (Sieb. ex Spreng.) Hooker 1853 [=Anacyclus australis Sieb. ex Spreng. 1826, Strongylosperma australe Less. 1832; incl. Cotula venosa Colenso 1891] A61

Cotula coronopifolia Linnaeus 1753 A61 [incl. C. integrifolia Hooker 1856 A61, C. coronopifolia var. integrifolia C06]

*Type species of generic name indicated

REFERENCES

[A61] Allan, H. H. 1961. Flora of New Zealand vol. 1. Indigenous Tracheophyta: Psilopsida, Lycopsida, Filicopsida, Gymnospermae, Dicotyledones. R. E. Owen, Government Printer: Wellington (New Zealand).

[BR65] Black, J. M., & E. L. Robertson. 1965. Flora of South Australia. Part IV. Oleaceae–Compositae. W. L. Hawes, Government Printer: Adelaide.

[C06] Cheeseman, T. F. 1906. Manual of the New Zealand Flora. John Mackay, Government Printer: Wellington.

[D03] Dusén, P. 1903. The vegetation of western Patagonia. In: Scott, W. B. (ed.) Reports of the Princeton University Expeditions to Patagonia, 1896–1899 vol. 8. Botany pp. 1–34. The University: Princeton (New Jersey).

[GK00] Gibson, N., & G. J. Keighery. 2000. Flora and vegetation of the Byenup-Muir reserve system, south-west Western Australia. CALMScience 3 (3): 323–402.

[VB02] Vijay, S. K., & T. N. Bhardwaja. 2002. Vegetation and phenodynamics of wetlands of central Rajasthan. Journal of the Bombay Natural History Society 99 (3): 573–581.