Cotula australisHook.f.

Australian waterbuttons

WFO wfo-0000031494 Accepted WFO 2026-06 8 photographs CC0 / CC BY

Plate 1 figs. a–h · 8 separate observations

Cotula australis, photographed by Daniel Das
fig. a Daniel Das, CC0 1.0 / 2022-06-12 / obs. 205635994

Every figure is a research-grade observation under CC0, CC BY or CC BY-SA, rehosted with the photographer’s name, the licence and the observation it came from. Photographs under a NonCommercial licence are excluded from this site and are never stored, which costs us a great many pictures and is not negotiable.

The specimen a real sheet, in a real collection

Herbarium
The New York Botanical Garden
Accession
813704
Filed as
Cotula australis (Sieber ex Spreng.) Hook.fil.
Det. by
S. F. Smith 1992-01-01
Collected
F. Soares 1991-06-18
Origin
BR
The sheet
View the digitised specimen (CC BY 4.0)

A real pressed plant, in a real collection, under the accession number above. Not an illustration of one. The holding institution does not serve this sheet’s image to third parties, so there is no photograph here. The record is real and the link goes to it. Where we hold no openly licensed sheet for a species this section is simply absent, and where a sheet never recorded who determined it, that field stays empty rather than being filled in. Roughly half of all herbarium sheets never recorded a determiner, which is ordinary.

Native range 20 botanical countries

Regions where Cotula australis is native: Cape Provinces, Free State, KwaZulu-Natal, Lesotho, Madagascar, Northern Provinces, Zimbabwe, East Himalaya, West Himalaya, Chatham Is., Kermadec Is., New South Wales, New Zealand North, New Zealand South, Norfolk Is., Queensland, South Australia, Tasmania, Victoria, Western Australia Cape ProvincesFree StateKwaZulu-NatalLesothoMadagascarNorthern ProvincesZimbabweEast HimalayaWest HimalayaNew South WalesNew Zealand NorthNew Zealand SouthQueenslandSouth AustraliaTasmaniaVictoriaWestern Australia Chatham Is.Kermadec Is.Norfolk Is.
Native distribution of Cotula australis, after Kew’s World Checklist of Vascular Plants. Introduced, extinct and doubtful records are excluded, so this is where the plant is from, not everywhere it now grows. Regions too small to draw at this scale are marked with a dot.
RegionTDWG codeContinent
Chatham Is. CTM AUSTRALASIA
Kermadec Is. KER
New South Wales NSW
New Zealand North NZN
New Zealand South NZS
Norfolk Is. NFK
Queensland QLD
South Australia SOA
Tasmania TAS
Victoria VIC
Western Australia WAU
Cape Provinces CPP AFRICA
Free State OFS
KwaZulu-Natal NAT
Lesotho LES
Madagascar MDG
Northern Provinces TVL
Zimbabwe ZIM
East Himalaya EHM ASIA-TROPICAL
West Himalaya WHM

Region boundaries approximated from Natural Earth (public domain) and mapped to TDWG World Geographical Scheme for Recording Plant Distributions (WGSRPD) level-3 botanical countries (Brummitt 2001). Indicative, not the official WGSRPD geometry.

Flowering 448 in flower of 531 examined

Proportion of examined Cotula australis in flower, by month
Month In flower Examined Share 95% interval
Jan 44 48 92% 80% to 97%
Feb 23 25 92% 75% to 98%
Mar 48 58 83% 71% to 90%
Apr 59 76 78% 67% to 86%
May 24 31 77% 60% to 89%
Jun 34 40 85% 71% to 93%
Jul 24 27 89% 72% to 96%
Aug 46 55 84% 72% to 91%
Sep 52 58 90% 79% to 95%
Oct 50 58 86% 75% to 93%
Nov 24 26 92% 76% to 98%
Dec 20 29 69% 51% to 83%

Peak flowering in Nov. Each bar is the share of Cotula australis observations in which someone actually recorded the reproductive state and found the plant in flower, not the raw number of flowering records. That distinction matters: people observe plants far more in spring than in winter, so a bare count of flowering records partly measures when people go outside. Dividing by the number examined removes that. 448 of 531 examined observations were in flower, every one of them research grade. The whisker on each bar is a 95% Wilson interval. This is still a global aggregate and not a forecast for your garden: the same species flowers on different dates in different hemispheres. Where a species has fewer than 30 flowering records we do not draw this chart at all. Computed from 10.15468/dl.cgje2x.

When it blooms, where you are 1 state

StatePeaksObservations in flower
California Jan 87

Where it actually grows measured, from 1,966 observations

Condition 5th percentile Median 95th percentile
Coldest month, mean daily low 2.2 °C 7.2 °C 12.0 °C
Warmest month, mean daily high 17.9 °C 25.0 °C 32.6 °C
Annual rainfall 296 mm 728 mm 1,830 mm
Rainfall in the driest quarter 4 mm 92 mm 227 mm

It is found where winters are cool but frost is light or absent. This is not care advice and it is not a forecast. It is a measurement: we sampled the climate at every one of the 1,966 research-grade observations of Cotula australis that carry a coordinate, and this is the range those places actually span. The 5th and 95th percentiles are used rather than the minimum and maximum, because a single cultivated specimen in a heated conservatory should not widen a tropical plant's range to the Arctic.

This is not a hardiness zone. A USDA zone is the average annual extreme minimum temperature. The figure above is the mean daily minimum of the coldest month, which is a different quantity and is typically far warmer. Reading one as the other would place a plant several zones too warm, so we do not publish a hardiness zone, because we do not have one. Climate from CHELSA V2.1 (Karger et al. 2017); occurrences from 10.15468/dl.cgje2x.

Also published as 7 synonyms

A synonym is not an error. It is a record of botanists disagreeing, in print, about where this plant belongs. Each of these was somebody’s considered answer.

  • Anacyclus australis Sieber ex Spreng.
  • Cotula membranacea D.G.Lloyd
  • Cotula venosa Colenso
  • Lancisia australis Rydb.
  • Leptinella tenella (A.Cunn.) D.G.Lloyd & C.J.Webb
  • Soliva tenella A.Cunn.
  • Strongylosperma australe Less.

Sourcesevery claim on this page

  1. World Flora Online Plant List. accepted name, authority, classification. CC0. Retrieved 2026-07-12.
  2. iNaturalist. photographs and flowering annotations, CC0 / CC BY / CC BY-SA only. per photograph. Retrieved 2026-06-27.
  3. Wikidata. common name (P1843), joined on the World Flora Online identifier (P7715). CC0. Retrieved 2026-07-13.
  4. Kew, World Checklist of Vascular Plants (WCVP v16). native distribution by TDWG level-3 botanical country, and life form. CC BY 3.0. Retrieved 2026-06-04.

We publish what we can source and we say so when we cannot. This page has no care advice and no toxicity claim, because we do not yet have those from a source we can cite.