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Commelina virginica; photograph (c) Ryan Sorrells, some rights reserved (CC BY) CC BY(c) Ryan Sorrells, some rights reserved (CC BY) · observed growing wild · 2026-09-09

Commelina virginica L.

Virginia dayflower

Commelinaceae · Illinois, Kansas +22

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Commelina virginica, photograph (c) David Wilkins, some rights reserved (CC BY)Commelina virginica, photograph (c) David Wilkins, some rights reserved (CC BY)Commelina virginica, photograph (c) stephen, some rights reserved (CC BY)Commelina virginica, photograph (c) Ryan Sorrells, some rights reserved (CC BY)Commelina virginica, photograph author not stated, no rights reservedCommelina virginica, photograph author not stated, no rights reserved 69 photographs ›
Habitat figures
Cold floor (1 night in 100)
-8.4°C
Record low -25.2 °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)
1,268mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
15–40DLI
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
Rain spread: 70% of the median year's rain takes 9 months, so no short rainy season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Commelina virginica, commonly known as the Virginia dayflower, is a perennial herbaceous plant in the dayflower family. It is native to the mideastern and southeastern United States, where it is typical of wet soils. While most members of the genus have thin, fibrous roots, the Virginia dayflower is unusual for its genus in having a perennial rhizome. The plant was first described by Carl Linnaeus in his 1762 publication of the second edition of Species Plantarum. More on Wikipedia ›

Quoted from Wikipedia, "Commelina virginica", CC BY-SA 4.0.

About the genus · Commelina

Commelina is a genus of approximately 208 species commonly called dayflowers due to the short lives of their flowers, and less often known as widow's tears. It is by far the largest genus of its family, Commelinaceae. The Swedish taxonomist Carl Linnaeus of the 18th century named the genus after the two Dutch botanists Jan Commelijn and his nephew Caspar, each representing one of the showy petals of Commelina communis.

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

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (966 mm of 1,252 mm) takes 9 months, March to September and November to December. Mean temperature moves 21.6 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: September to March and May to June.

Rain

1,252 mm in the median year at the habitat, 966 mm of it March to September and November to December. Wettest months (2 at 116 mm), driest month October at 93 mm. Across the grid cells of the range the year's total runs 1,119 mm to 1,504 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,268 mm, is the year's rain at the top of the page; the 1,252 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: 15 to 40 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 13, the highest 90th-percentile month 41).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -8.4 °C, the absolute minimum -25.2 °C, 2,990 frost nights in 44 years, 68.0 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 38.0 °C. Monthly means: the coldest month's mean nightly low 1.0 °C in January (across the grid cells of the range -2.1 °C to 6.5 °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: -8.4 °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: 56 to 60% 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 -43 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 Commelina virginica through the yearWarmest month July, mean daily high 32 °C; coldest month January, mean nightly low 1.0 °C; 1,252 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.-40°-20°0°20°40°frost38.0° 99th-percentile day, NASA POWER-25.2° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200mm rainDLI 15–40RH 56–60%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 962 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 °C10 / 6–1613 / 8–1817 / 14–2122 / 19–2526 / 24–2930 / 28–3232 / 30–3331 / 30–3328 / 26–3022 / 20–2616 / 14–2111 / 8–17
Night °C1 / -2–73 / -1–86 / 4–1111 / 9–1516 / 14–1920 / 19–2322 / 21–2422 / 21–2418 / 17–2113 / 11–167 / 6–123 / 0–8
Rain mm95 / 74–13898 / 73–142112 / 92–138102 / 81–128116 / 88–145109 / 96–152116 / 94–147101 / 73–13799 / 82–12493 / 81–133106 / 79–130105 / 82–149
DLI17 / 15–1821 / 20–2328 / 27–3035 / 34–3739 / 37–4040 / 39–4139 / 38–4136 / 34–3830 / 28–3224 / 22–2618 / 16–2015 / 13–17
RH %58 / 56–5957 / 55–5956 / 55–5956 / 54–5858 / 56–6059 / 58–6160 / 58–6260 / 57–6259 / 56–6057 / 56–5858 / 56–5959 / 57–60
How this section is made
Each figure is the median across the 962 grid cells on land that hold in-range records (1466 records in those cells; 2 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 1082:2020 (35.875, -78.975). Over 44 years there: absolute minimum -25.2 °C, 1st-percentile night -8.4 °C, 99th-percentile day 38.0 °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 962 distinct grid cells holding 1466 of the 1468 in-range records (2 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1082:2020 (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 36.00_-78.750, lapse-corrected -43 m at 6.5 °C/km. Elevation: ETOPO 2022, 80 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.
NativeIllinois, Kansas, Missouri, Oklahoma, Indiana, New Jersey, Ohio, Pennsylvania, West Virginia, Texas, Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, District of Columbia · introduced: Japan, Myanmar, Puerto Rico · 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 marker33.853, -84.572 · in the densest population, 1006 records (58% 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 1730 georeferenced records inside the native range; the climate across the range on the 1466 of them in the land cells it reads, of 1468 placed to within 10 km; the map shows only the 439 openly licensed ones, which alone would put the marker 1266 km away. 35 records outside the WCVP native range not used. 262 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 1730 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Commelina virginica, photograph 1did not loadCommelina virginica, photograph 2did not loadCommelina virginica, photograph 3did not loadCommelina virginica, photograph 4did not loadCommelina virginica, photograph 5did not loadCommelina virginica, photograph 6did not load

Photographs: (c) David Wilkins, some rights reserved (CC BY) (2); (c) stephen, some rights reserved (CC BY); (c) Ryan Sorrells, some rights reserved (CC BY); author not stated, no rights reserved · CC0 (2).

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

Clitoria mariana Clitoria mariana Butterfly-pea Photo: CC BY, Anne ParkerArundinaria gigantea Arundinaria gigantea Giant cane Photo: CC BY, Ryan SorrellsStylosanthes biflora Stylosanthes biflora Sidebeak pencil-flower Photo: CC BY, Ryan SorrellsAgave virginica Agave virginica Asparagaceae Photo: CC0, John KeesAsclepias variegata Asclepias variegata Red-ring milkweed Photo: CC0, author not statedFrangula caroliniana Frangula caroliniana Carolina buckthorn Photo: CC BY, Eliza Crofts

Other Commelina 15 in the reference

Commelina africana Commelina africana African Yellow Dayflower Photo: CC BY, Liezl van der MerweCommelina auriculata Commelina auriculata Commelinaceae Photo: CC BY-SA, vrxzCommelina benghalensis Commelina benghalensis Day flower Photo: CC BY, AparnaCommelina capitata Commelina capitata Commelinaceae Photo: CC BY, Jean Jacques GodonCommelina communis Commelina communis Asiatic dayflower Photo: CC BY, Nathan AaronCommelina cyanea Commelina cyanea Creeping Christian Photo: CC BY-SA, Greg TasneyCommelina dianthifolia Commelina dianthifolia Birdbill dayflower Photo: CC BY, CK2AZCommelina diffusa Commelina diffusa Climbing dayflower Photo: CC BY, Nathan AaronCommelina ensifolia Commelina ensifolia Commelinaceae Photo: CC BY, Cody HinchliffCommelina erecta Commelina erecta Erect dayflower Photo: CC BY, Catherine C. GalleyCommelina forskaolii Commelina forskaolii Rat's ear Photo: CC0, author not stated Commelina leiocarpa Smooth-fruited Dayflower all 16 ›

Names & registers

Also known as Allotria scabra; Commelina caerulea; Commelina deficiens; Commelina hirtella; Commelina longifolia and 2 more. (GBIF Backbone)

Under another author Commelina auriculata E.Mey. is an older name of this species, not Commelina auriculata, a species of the reference. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Commelinaceae
Described by
L.
Native to
Illinois, Kansas, Missouri +21
Wild records
1730 in range · 439 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; 50 records within 1 km of a botanic garden, herbarium or zoo left out (45 at a botanic garden or arboretum, 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 36.00_-78.750, lapse-corrected -43 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 91 datasets via GBIF.org; each carries its own licence.

Cultifolio

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