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Ludwigia peruviana; photograph (c) Wolfgang Ahlmer, some rights reserved (CC BY) CC BY(c) Wolfgang Ahlmer, some rights reserved (CC BY) · observed growing wild · 2026-08-12

Ludwigia peruviana (L.) H.Hara

Peruvian primrose-willow; Peruvian primrosebush; Water-primrose; Primrose-willow

Onagraceae · Mexico Gulf, Mexico Southwest +28

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Ludwigia peruviana, photograph (c) Wolfgang Ahlmer, some rights reserved (CC BY)Ludwigia peruviana, photograph (c) xanderferret, some rights reserved (CC BY)Ludwigia peruviana, photograph (c) xanderferret, some rights reserved (CC BY)Ludwigia peruviana, photograph (c) xanderferret, some rights reserved (CC BY)Ludwigia peruviana, photograph author not stated, no rights reservedLudwigia peruviana, photograph (c) James Hardee, some rights reserved (CC BY) 76 photographs ›
Habitat figures
Coldest month, mean nightly low
13.9°C
Jan at the habitat, not a floor; extremes not used (the weather cell's ground is too far off) CHELSA
Warmest month, mean daily high
24°C
Mar, Apr and May at the habitat CHELSA
Rain a year (median across the range)
1,888mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
29–36DLI
Lowest to highest month (DLI) CHELSA
The year in the habitat's months, not shifted
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
A sharp rainy season, May to November (the habitat's months, not shifted), in a year of even temperature. rain rule, CHELSA
Not shifted: the shift rule does not apply to this habitat. The chart is in the habitat's months.

Summary

Ludwigia peruviana, with the common names Peruvian primrose-willow or Peruvian water primrose, is an aquatic, sometimes deciduous species of flowering plant in the evening primrose family. It can grow to approximately 12 feet (3.7 m) in height. While native to Peru, it has been introduced in many other countries for its attractive simple yellow flowers, it is now a common weed in swampy areas around the world.

Quoted from Wikipedia, "Ludwigia peruviana", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a sharp season: 70% of the median year's rain (1,456 mm of 1,966 mm) falls in May to November. The temperature curve is flat, 2.4 °C between the warmest and coldest month, so the growing-season rule does not infer a growing season from it. Months are the habitat's, northern hemisphere. The habitat lies within 10° of the equator, where the shift rule does not apply, so they are not shifted for a collection elsewhere.

Rain

1,966 mm in the median year at the habitat, 1,456 mm of it May to November. Wettest month September at 256 mm, driest month January at 74 mm. Across the grid cells of the range the year's total runs 1,067 mm to 4,107 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,888 mm, is the year's rain at the top of the page; the 1,966 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: 29 to 36 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 23, the highest 90th-percentile month 42).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low 13.9 °C in January (across the grid cells of the range 8.7 °C to 19.4 °C), the warmest month's mean daily high 23.7 °C in April (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 13.9 °C, the coldest month's mean nightly low, January, in the median year (CHELSA); a month's mean of its nightly lows is warmer than the nights a floor is read from. The daily extremes were read at a weather cell whose ground is too far above or below the typical spot to correct for, and are not used.

Humidity

Relative humidity at the habitat: 64 to 68% 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. CHELSA monthly means, median year across the grid cells of the range. No cold floor is read without a daily extremes series; the coldest month's mean nightly low named in its sentence is not one. 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 Ludwigia peruviana through the yearWarmest months March, April and May, mean daily high 24 °C; coldest month January, mean nightly low 13.9 °C; 1,966 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, northern hemisphere.5°10°15°20°25°30°35°°C · day and nightcold quarter0100200300400500600mm rainDLI 29–36RH 64–68%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 89 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C22 / 19–2822 / 19–2924 / 19–2924 / 19–3024 / 18–3023 / 18–2923 / 18–2823 / 19–2923 / 19–2823 / 19–2822 / 18–2822 / 18–27
Night °C14 / 9–1914 / 9–2015 / 10–2016 / 11–2116 / 10–2216 / 10–2215 / 10–2115 / 9–2116 / 10–2115 / 10–2115 / 10–2014 / 9–20
Rain mm74 / 25–18780 / 26–178107 / 27–241152 / 44–343189 / 85–460222 / 65–501200 / 57–496212 / 55–477256 / 73–456222 / 117–465155 / 58–34397 / 32–215
DLI31 / 24–3433 / 28–3735 / 29–4036 / 27–4233 / 26–4132 / 25–3834 / 26–3935 / 29–3933 / 27–3930 / 25–3629 / 23–3329 / 23–33
RH %65 / 57–7264 / 57–7264 / 58–7265 / 60–7366 / 62–7367 / 62–7566 / 60–7366 / 59–7268 / 60–7368 / 62–7467 / 63–7566 / 60–73

Records on both sides of the equator: the 33 cells at least 10° south of it have seasons six months apart and are left out, not combined into a year no place has. These figures are across the 89 cells that remain: the 39 at least 10° north and the 50 within 10° of the equator, which stay in either way.

The daily extremes were not used: the correction for elevation, -1419 m, is beyond the 1,000 m either way that a lapse rate is applied over, so the weather cell's ground is other terrain than the typical spot's. So no cold floor is read for this species, and the coldest month's mean nightly low is not taken as one. What that cell gave, so corrected, over 44 years: absolute minimum 9.6 °C, 1st-percentile night 12.1 °C.

How this section is made
Each figure is the median across the 89 grid cells on land that hold in-range records (99 records in those cells; 1 more cell holds records but no land by the elevation layer, so those records sit at sea and the cell is left out), 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 1841:2020 (-2.075, -78.975). 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 89 distinct grid cells holding 99 of the 134 in-range records (1 further cell with records at sea, by the elevation layer, left out) on the northern side of the equator (39 cells poleward of 10° north, 33 poleward of 10° south: the two sides' seasons are not combined, and cells within 10° of the equator stay in); extremes and elevation at the typical cell 1841:2020 (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 -2.00_-78.750, lapse-corrected -1419 m at 6.5 °C/km. Elevation: ETOPO 2022, 1565 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 Gulf, Mexico Southwest, Mexico Southeast, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Cuba, Dominican Republic, Haiti, Jamaica, Puerto Rico, Trinidad-Tobago, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil West-Central, Brazil Southeast, Brazil North, Brazil South, Argentina Northeast, Argentina Northwest, Chile Central, Paraguay, Uruguay · introduced: Mauritius, Taiwan, Assam, India, Sri Lanka, Andaman Is., Thailand, Borneo, Jawa, Malaya, Sumatera, New South Wales, Society Is., Texas, Alabama, Florida, Georgia, Louisiana, North Carolina · 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 marker4.65, -74.107 · in the densest population, 94 records (27% of those in range)
Kew's description“subshrub or shrub” · “wet tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 348 georeferenced records inside the native range; the climate across the range on the 99 of them in the land cells it reads, of 134 placed to within 10 km; the map shows only the 258 openly licensed ones, which alone would put the marker 4626 km away. 870 records outside the WCVP native range not used. 214 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 inside the densest 4° block of the 348 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Ludwigia peruviana, photograph 1did not loadLudwigia peruviana, photograph 2did not loadLudwigia peruviana, photograph 3did not loadLudwigia peruviana, photograph 4did not loadLudwigia peruviana, photograph 5did not loadLudwigia peruviana, photograph 6did not load

Photographs: (c) Wolfgang Ahlmer, some rights reserved (CC BY); (c) xanderferret, some rights reserved (CC BY) (3); author not stated, no rights reserved · CC0; (c) James Hardee, some rights reserved (CC BY).

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

Passiflora adenopoda Passiflora adenopoda Passifloraceae Photo: CC BY, Nicolás Baresch UribePrescottia stachyodes Prescottia stachyodes Mountain Prescott orchid Photo: CC BY, Guillaume DelaitreFurcraea cabuya Furcraea cabuya Asparagaceae Photo: CC BY, Daniel MesaTurpinia occidentalis Turpinia occidentalis Muttonwood Photo: CC BY, Giovanny VargasCyclopogon elatus Cyclopogon elatus Tall ladies'-tresses Photo: CC0, author not statedStelis gelida Stelis gelida Flor de Llanten Photo: CC BY-SA, Jeanette Clarke

Other Ludwigia 29 in the reference

Ludwigia adscendens Ludwigia adscendens Water primrose Photo: CC BY, yelena_antipovaLudwigia alata Ludwigia alata Winged primrose-willow Photo: CC BY, Devin FloydLudwigia alternifolia Ludwigia alternifolia Rattlebox Photo: CC BY, Alexander DiazLudwigia arcuata Ludwigia arcuata Piedmont primrose-willow Photo: CC BY, James HardeeLudwigia bonariensis Ludwigia bonariensis Carolina primrose-willow Photo: CC BY, Germinando NativasLudwigia brevipes Ludwigia brevipes Long Beach primrose willow Photo: CC BY, harrierLudwigia decurrens Ludwigia decurrens Wingleaf primrose-willow Photo: CC BY, M. WhitsonLudwigia elegans Ludwigia elegans Onagraceae Photo: CC BY, Ernesto Fernandez PolcuchLudwigia erecta Ludwigia erecta Yerba de jicotea Photo: CC BY, Cricket RaspetLudwigia glandulosa Ludwigia glandulosa Cylindricfruit primrose-willow Photo: CC BY, carterLudwigia grandiflora Ludwigia grandiflora Water primrose Photo: CC0, author not statedLudwigia helminthorrhiza Ludwigia helminthorrhiza Floating Ludwigia Photo: CC BY, Gabriel Jovêncio Ribeiro all 30 ›

Names & registers

Also known as Jussiaea grandiflora; Jussiaea hirsuta; Jussiaea hirta; Jussiaea macrocarpa; Jussiaea mollis and 18 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Onagraceae
Described by
(L.) H.Hara
Native to
Mexico Gulf, Mexico Southwest, Mexico Southeast +27
Wild records
348 in range · 258 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 2026-10-22
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
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; 41 records within 1 km of a botanic garden, herbarium or zoo left out (32 at a botanic garden or arboretum, 1 at a herbarium, 8 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell -2.00_-78.750, lapse-corrected -1419 m at 6.5 °C/km; read, and set aside: the correction for elevation, -1419 m, is beyond the 1,000 m either way that a lapse rate is applied over, so the weather cell's ground is other terrain than the typical spot's, so no cold floor is shown
Wikidata wikidata answeredasked 2026-10-22
Wikipedia wikipedia answeredasked 2026-10-22
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 2026-10-22
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 104 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…