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Ageratum conyzoides; photograph (c) Luke Lythgoe, some rights reserved (CC BY) CC BY(c) Luke Lythgoe, some rights reserved (CC BY) · observed growing wild · 2026-09-11

Ageratum conyzoides L.

Tropical whiteweed; Billygoat-weed; Goatweed; Whiteweed

Asteraceae · Mexico Central, Mexico Northeast +3

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Ageratum conyzoides, photograph (c) Ong Jyh Seng, some rights reserved (CC BY)Ageratum conyzoides, photograph (c) Harrison Cole, some rights reserved (CC BY)Ageratum conyzoides, photograph (c) Brynn Fricke, some rights reserved (CC BY)Ageratum conyzoides, photograph (c) Brynn Fricke, some rights reserved (CC BY)Ageratum conyzoides, photograph (c) Nathan Nguyen, some rights reserved (CC BY)Ageratum conyzoides, photograph (c) Nathan Nguyen, some rights reserved (CC BY) 72 photographs ›
Habitat figures
Cold floor (1 night in 100)
6.9°C
Record low -3.9 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
29°C
May at the habitat CHELSA
Rain a year (median across the range)
1,714mm
9 months of 25 mm or more in the median year CHELSA
Open-sky light
26–43DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Wet summers: the rain comes June to September, read as a summer growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Ageratum conyzoides (billygoat-weed, chick weed, goatweed, whiteweed, mentrasto) is native to Tropical America, especially Brazil, and is an invasive weed in many other regions. It is an herb that is 0.5–1 m. high, with ovate leaves 2–6 cm long, and flowers are white to mauve.

Quoted from Wikipedia, "Ageratum conyzoides", CC BY-SA 4.0.

About the genus · Ageratum

Ageratum is a genus of 40 to 60 tropical and warm temperate flowering annuals and perennials from the family Asteraceae, tribe Eupatorieae. Most species are native to Central America and Mexico but four are native to the United States.

Quoted from Wikipedia, "Ageratum", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (1,271 mm of 1,639 mm) falls in June to September, warmer than the year (wet-season mean 23.4 °C against a yearly mean of 21.4 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: December to March.

Rain

1,639 mm in the median year at the habitat, 1,271 mm of it June to September. Wettest month July at 368 mm, driest month March at 14 mm. Across the grid cells of the range the year's total runs 1,190 mm to 2,585 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,714 mm, is the year's rain at the top of the page; the 1,639 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 26 to 43 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA; the lowest 10th-percentile month across the cells is 21, the highest 90th-percentile month 49).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 6.9 °C, the absolute minimum -3.9 °C, 5 frost nights in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 34.6 °C. Monthly means: the coldest month's mean nightly low 12.9 °C in January (across the grid cells of the range 11.9 °C to 19.0 °C), the warmest month's mean daily high 29.3 °C in May (median year across the grid cells of the range, CHELSA). Cold floor: 6.9 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 59 to 69% across the year (monthly means, median year across the grid cells of the range, CHELSA). A figure about the air, saying nothing about how the plant takes water.

How this section is made

Each card states this species' habitat figures with their sources, and what two fixed rules read from them; nothing here says what the plant does, wants or tolerates. The rules · the terms.

Seasons. Read from the median year of CHELSA monthly rainfall and mean temperature across the grid cells of the range: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve moves 4 °C or more and the habitat lies 10° or more from the equator. A reading of the curves, not an observation of the plant.

Rain. CHELSA monthly precipitation, median year across the grid cells of the range. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light. CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Temperature. NASA POWER daily minima and maxima over 44 years at a typical spot in the range, lapse-corrected +226 m to its elevation; CHELSA monthly means, median year across the grid cells of the range. The cold floor is the 1st-percentile night named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity. CHELSA relative humidity, median year across the grid cells of the range.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Ageratum conyzoides through the yearWarmest month May, mean daily high 29 °C; coldest month January, mean nightly low 12.9 °C; 1,639 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, northern hemisphere.-10°0°10°20°30°40°frost34.6° 99th-percentile day, NASA POWER-3.9° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 26–43RH 59–69%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 12 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C24 / 20–2625 / 22–2726 / 24–2928 / 26–3129 / 26–3228 / 24–3127 / 24–3027 / 24–3026 / 24–2926 / 23–2826 / 22–2825 / 21–26
Night °C13 / 12–1914 / 12–2015 / 12–2117 / 14–2319 / 16–2520 / 19–2520 / 18–2420 / 18–2420 / 18–2418 / 17–2316 / 15–2114 / 13–20
Rain mm38 / 13–8518 / 13–7914 / 5–7924 / 2–12162 / 8–145243 / 164–317368 / 245–410342 / 215–407318 / 232–470146 / 77–32741 / 18–16725 / 17–99
DLI27 / 22–3332 / 25–3840 / 31–4443 / 35–4842 / 38–4938 / 34–4035 / 33–3835 / 33–3732 / 29–3331 / 27–3329 / 24–3326 / 21–31
RH %61 / 55–7062 / 55–6860 / 54–6659 / 52–6662 / 55–6666 / 63–6967 / 64–7168 / 65–7269 / 64–7166 / 62–7062 / 59–6862 / 57–69
How this section is made
Each figure is the median across the 12 grid cells holding the 12 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 1403:1662 (19.825, -96.875). Over 44 years there: absolute minimum -3.9 °C, 1st-percentile night 6.9 °C, 99th-percentile day 34.6 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 12 distinct grid cells holding 12 of the 12 in-range records; extremes and elevation at the typical cell 1403:1662 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 20.00_-96.875, lapse-corrected +226 m at 6.5 °C/km. Elevation: ETOPO 2022, 824 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeMexico Central, Mexico Northeast, Mexico Gulf, Mexico Northwest, Mexico Southwest · introduced: Germany, France, Bulgaria, Italy, Yugoslavia, Egypt, Cape Verde, Madeira, Benin, Burkina, Guinea-Bissau, Guinea, Ivory Coast, Mali, Mauritania, Nigeria, Senegal, Togo, Central African Republic, Cameroon, Congo, Gabon, Gulf of Guinea Is., Rwanda, Zaïre, Chad, Ethiopia, Socotra, Sudan, Kenya, Angola, Mozambique, Zambia, Zimbabwe, Botswana, Cape Provinces, KwaZulu-Natal, Swaziland, Northern Provinces, Chagos Archipelago, Comoros, Mauritius, Madagascar, Réunion, Rodrigues, Seychelles, Uzbekistan, North Caucasus, Transcaucasus, Palestine, Oman, Saudi Arabia, China South-Central, Hainan, China North-Central, China Southeast, Korea, Kazan-retto, Nansei-shoto, Ogasawara-shoto, Taiwan, Assam, Bangladesh, East Himalaya, India, Laccadive Is., Maldives, Nepal, Pakistan, Sri Lanka, West Himalaya, Andaman Is., Cambodia, Laos, Myanmar, South China Sea, Thailand, Vietnam, Jawa, Malaya, Philippines, Christmas I., Norfolk Is., New South Wales, Northern Territory, Queensland, Fiji, Niue, New Caledonia, Samoa, Tonga, Vanuatu, Cook Is., Marquesas, Society Is., Tuamotu, Tubuai Is., Caroline Is., Marianas, Marshall Is., Hawaii, Missouri, Connecticut, California, Alabama, Florida, Georgia, Kentucky, Maryland, Mississippi, North Carolina, Costa Rica, Panama, Bahamas, Cuba, Dominican Republic, Haiti, Leeward Is. AB Ant, Puerto Rico, Turks-Caicos Is., Trinidad-Tobago, Venezuelan Antilles, Windward Is., French Guiana, Guyana, Surinam, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil North, Brazil South, Argentina Northeast, Argentina Northwest, Paraguay, Uruguay · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker19.849, -96.871 · in the densest population, 9 records (60% of those in range)
Kew's description“annual or subshrub” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 15 georeferenced records inside the native range; the climate across the range on the 12 of them placed to within 10 km; the map shows only the 13 openly licensed ones, which alone would put the marker in the same place. 1691 records outside the WCVP native range not used. 3 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population of the 15 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Ageratum conyzoides, photograph 1did not loadAgeratum conyzoides, photograph 2did not loadAgeratum conyzoides, photograph 3did not loadAgeratum conyzoides, photograph 4did not loadAgeratum conyzoides, photograph 5did not loadAgeratum conyzoides, photograph 6did not load

Photographs: (c) Ong Jyh Seng, some rights reserved (CC BY); (c) Harrison Cole, some rights reserved (CC BY); (c) Brynn Fricke, some rights reserved (CC BY) (2); (c) Nathan Nguyen, some rights reserved (CC BY) (2).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Sigmoidotropis speciosa Sigmoidotropis speciosa Snail flower Photo: CC BY-SA, Matt LavinAphananthe monoica Aphananthe monoica Cannabaceae Photo: CC BY, Ricardo Betancourt SánchezXanthosoma robustum Xanthosoma robustum Capote Photo: CC BY, florawhiteTillandsia compressa Tillandsia compressa Bromeliaceae Photo: CC0, author not statedCalea urticifolia Calea urticifolia Asteraceae Photo: CC BY, Alberto AlcaláTillandsia ionantha Tillandsia ionantha Blushing Bride Photo: CC BY, Tereso Hernández Morales

Other Ageratum 4 in the reference

Ageratum corymbosum Ageratum corymbosum Flat-top Ageratum Photo: CC BY, Alexis López HernándezAgeratum houstonianum Ageratum houstonianum Bluemink Photo: CC BY, Ankit ShakyaAgeratum littorale Ageratum littorale Cape Sable whiteweed Photo: CC BY, Dominic GentilcoreAgeratum maritimum Ageratum maritimum Cape Sable whiteweed Photo: CC BY, Eddie

Names & registers

Also known as Ageratum album; Ageratum arsenei; Ageratum brachystephanum; Ageratum caeruleum; Ageratum ciliare and 46 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Asteraceae
Described by
L.
Native to
Mexico Central, Mexico Northeast, Mexico Gulf +2
Wild records
15 in range · 13 open

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-21
GBIF species record gbif.species answeredasked 2026-10-21
GBIF synonyms gbif.synonyms answeredasked 2026-10-21
GBIF common names gbif.vernacular answeredasked 2026-10-21names fetched 2026-10-21
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 23 records within 1 km of a botanic garden, herbarium or zoo left out (14 at a botanic garden or arboretum, 4 at a herbarium, 5 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-21
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-21NASA POWER (MERRA-2) daily 1981–2024, cell 20.00_-96.875, lapse-corrected +226 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-21
Wikipedia wikipedia answeredasked 2026-10-21
iNaturalist photographs, wild inat.photos.wild answeredasked 2026-10-22from iNaturalist's open data of 2026-09-27: research-grade observations with an open-licence photograph, the 24 whose photographs iNaturalist received last (the open data holds no votes); filled 2026-10-22
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-21
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 244 datasets via GBIF.org; each carries its own licence.

Cultifolio

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