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Ludwigia repens; photograph (c) James Hardee, some rights reserved (CC BY) CC BY(c) James Hardee, some rights reserved (CC BY) · observed growing wild · 2026-09-02

Ludwigia repens J.R.Forst.

Creeping primrose-willow; Creeping waterpurslane; Larger marsh purslane

Onagraceae · Oregon, Kansas +31

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Ludwigia repens, photograph (c) James Hardee, some rights reserved (CC BY)Ludwigia repens, photograph (c) James Hardee, some rights reserved (CC BY)Ludwigia repens, photograph (c) James Hardee, some rights reserved (CC BY)Ludwigia repens, photograph (c) James Hardee, some rights reserved (CC BY)Ludwigia repens, photograph (c) James Hardee, some rights reserved (CC BY)Ludwigia repens, photograph (c) James Hardee, some rights reserved (CC BY) 101 photographs ›
Habitat figures
Cold floor (1 night in 100)
0.3°C
Record low -8.7 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
32°C
Jul at the habitat CHELSA
Rain a year (median across the range)
1,351mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
20–41DLI
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 May to October, 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

Ludwigia repens is a species of flowering plant in the evening primrose family known by the common name creeping primrose-willow. It is native to parts of the Americas and it has the potential to spread easily and become naturalized in many areas. It is known as an aquatic weed in some regions. It is also cultivated as an aquarium plant. More on Wikipedia ›

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

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (917 mm of 1,306 mm) falls in May to October, warmer than the year (wet-season mean 26.1 °C against a yearly mean of 22.1 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to April.

Rain

1,306 mm in the median year at the habitat, 917 mm of it May to October. Wettest month August at 189 mm, driest month January at 54 mm. Across the grid cells of the range the year's total runs 832 mm to 1,549 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,351 mm, is the year's rain at the top of the page; the 1,306 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: 20 to 41 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 17, the highest 90th-percentile month 44).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 0.3 °C, the absolute minimum -8.7 °C, 143 frost nights in 44 years, 3.3 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 36.8 °C. Monthly means: the coldest month's mean nightly low 11.6 °C in January (across the grid cells of the range 3.8 °C to 16.4 °C), the warmest month's mean daily high 31.6 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: 0.3 °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: 57 to 63% 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 -13 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 Ludwigia repens through the yearWarmest month July, mean daily high 32 °C; coldest month January, mean nightly low 11.6 °C; 1,306 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°frost36.8° 99th-percentile day, NASA POWER-8.7° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200250300mm rainDLI 20–41RH 57–63%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 396 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 °C21 / 14–2422 / 16–2624 / 20–2727 / 23–3029 / 27–3231 / 29–3232 / 30–3431 / 30–3430 / 28–3127 / 24–2925 / 19–2722 / 14–25
Night °C12 / 4–1613 / 6–1715 / 9–1817 / 13–2020 / 17–2323 / 21–2524 / 22–2524 / 22–2523 / 19–2520 / 15–2316 / 10–2013 / 5–18
Rain mm54 / 26–10066 / 21–9785 / 22–11666 / 45–8995 / 61–132183 / 101–254174 / 55–228189 / 53–245173 / 77–232103 / 68–13961 / 25–9857 / 22–97
DLI22 / 18–2427 / 23–2933 / 29–3639 / 35–4241 / 37–4339 / 38–4240 / 37–4437 / 34–4132 / 30–3527 / 26–3123 / 20–2620 / 17–23
RH %58 / 57–6058 / 56–6057 / 55–5957 / 55–5959 / 57–6162 / 57–6362 / 55–6463 / 53–6463 / 55–6460 / 55–6159 / 56–6058 / 57–60
How this section is made
Each figure is the median across the 396 grid cells on land that hold in-range records (559 records in those cells; 3 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are 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 1224:1979 (28.775, -81.025). Over 44 years there: absolute minimum -8.7 °C, 1st-percentile night 0.3 °C, 99th-percentile day 36.8 °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 396 distinct grid cells holding 559 of the 562 in-range records (3 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1224:1979 (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 29.00_-81.250, lapse-corrected -13 m at 6.5 °C/km. Elevation: ETOPO 2022, 3 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.
NativeOregon, Kansas, Missouri, Oklahoma, New Jersey, Arizona, California, Nevada, New Mexico, Texas, Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Mexico Central, Mexico Northeast, Mexico Gulf, Mexico Southwest, Mexico Southeast, El Salvador, Bahamas, Bermuda, Cuba, Dominican Republic, Haiti, Jamaica, Puerto Rico · introduced: Austria, Czechoslovakia, Germany, Hungary, Spain, Bangladesh · 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 marker25.393, -80.65 · in the densest population, 325 records (39% of those in range)
Kew's description“perennial” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 834 georeferenced records inside the native range; the climate across the range on the 559 of them in the land cells it reads, of 562 placed to within 10 km; the map shows only the 355 openly licensed ones, which alone would put the marker 153 km away. 131 records outside the WCVP native range not used. 272 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 834 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 repens, photograph 1did not loadLudwigia repens, photograph 2did not loadLudwigia repens, photograph 3did not loadLudwigia repens, photograph 4did not loadLudwigia repens, photograph 5did not loadLudwigia repens, photograph 6did not load

Photographs: (c) James Hardee, some rights reserved (CC BY) (6).

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

Buchnera floridana Buchnera floridana Florida bluehearts Photo: CC BY, carterHypericum tenuifolium Hypericum tenuifolium Atlantic St. Johnswort Photo: CC BY, Ashwin SrinivasanBejaria racemosa Bejaria racemosa Flyweed Photo: CC BY, geosesarmaHabenaria floribunda Habenaria floribunda Toothpetal bog orchid Photo: CC BY, Milo CatonHypericum fasciculatum Hypericum fasciculatum Peelbark St. Johnswort Photo: CC BY, Karen GuinPhysostegia purpurea Physostegia purpurea False Dragonhead Photo: CC BY, Ashwin Srinivasan

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 Isnardia intermedia; Isnardia media; Isnardia natans; Isnardia repens; Isnardia repens var. rotundata and 9 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Onagraceae
Described by
J.R.Forst.
Native to
Oregon, Kansas, Missouri +30
Wild records
834 in range · 355 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; 24 records within 1 km of a botanic garden, herbarium or zoo left out (17 at a botanic garden or arboretum, 7 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 29.00_-81.250, lapse-corrected -13 m at 6.5 °C/km
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 119 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…