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brass-buttons, buttonweed, common brass-buttons, cotule, golden buttons

Australian cotula, Australian waterbuttons, brass buttons

Habit Perennials, (3–)5–15(–25+) cm tall or across. Annuals, 2–10(–25+) cm.
Stems

prostrate (rooting at nodes, ± fleshy) to decumbent or erect, glabrous.

branched ± throughout, ± strigillose to villous, glabrescent.

Leaves

sessile (bases sheathing stems);

blades linear to lanceolate or oblong (sometimes lobed, lobes lanceolate to linear), (1–)2–3(–7) cm, ultimate margins entire or irregularly toothed or lobed, faces gland-dotted.

petiolate or sessile;

blades obovate to spatulate, 2–3-pinnately lobed (ultimate lobes narrowly spatulate to linear), (1–)2–3(–6) cm.

Involucres

6–9(–12+) mm diam.

3–4(–6) mm diam.

Ray florets

0 (peripheral pistillate florets 12–40+ in 1 series; corollas 0).

0 (peripheral pistillate florets 8–80+ in 1–3+ series; corollas 0).

Disc corollas

yellow, 1–1.5 mm.

ochroleucous to pale yellow, 0.5–0.8 mm.

Phyllaries

21–30+ in 2–3+ series.

13–22+ in 2–3 series, subequal (apices brown).

Cypselae

outer 1.2–1.8 mm, winged, adaxial faces papillate;

inner 0.7–1 mm, scarcely, if at all, winged, not papillate.

outer stalked, 1–1.2 mm, ± winged, faces ± papillate;

inner sessile, 0.8–1 mm, not winged, not papillate.

2n

= 20.

= 36, 40.

Cotula coronopifolia

Cotula australis

Phenology Flowering Mar–Dec. Flowering Jan–Sep.
Habitat Saline and freshwater marshes, along streams Disturbed sites
Elevation 0–900 m [0–3000 ft] 0–800 m [0–2600 ft]
Distribution
from FNA
AK; AZ; CA; MA; MD; NV; OR; WA; BC; NB; NS; PE; QC; South America; S Africa; Australia; Europe [Presumed introduced; also introduced in Mexico (Baja California)]
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; FL; ME; OR; TX; South America; Australia; Africa [Introduced in North America; also introduced in Northern Hemisphere: Mexico (Baja California)]
[WildflowerSearch map]
[BONAP county map]
Source FNA vol. 19, p. 544. FNA vol. 19, p. 544.
Parent taxa Asteraceae > tribe Anthemideae > Cotula Asteraceae > tribe Anthemideae > Cotula
Sibling taxa
C. australis
C. coronopifolia
Synonyms Anacyclus australis
Name authority Linnaeus: Sp. Pl. 2: 892. (1753) (Sieber ex Sprengel) Hooker f.: Fl. Nov.-Zel. 1: 128. (1852)
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