Commelina erecta L.
Blousel Blommetjie, Blue Commelina, Coastal Blue Dayflower, Erect Dayflower
Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.
Summary
Commelina erecta, commonly known as white mouth dayflower, slender dayflower, or widow's tears. C. erecta is a blue flower often recognized by its two large blue petals and smaller white petal. It is a perennial herb common across the world and native throughout the Americas, Africa and western Asia.
Text from Wikipedia, “Commelina erecta”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.
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.
Text from Wikipedia, “Commelina”, CC BY-SA 4.0, quoted as written.
At a glance
Also known as Commelina albescens C.B.Clarke; Commelina auriculata E.May.; Commelina bahiensis Hoffmanns.; Commelina bahiensis Hoffmanns. ex Spreng.; Commelina bahiensis Willd. and 11 more.
Cultivation
Grouped as a tropical foliage plant by Commelinaceae, which is usually but not always one kind of plant (archetype table). The table supplies one figure for this group, a conventional minimum for the cold floor, and no prose.
Its year Rain rule: no season, 70% of the rain takes 8 months (March and May to November in the northern hemisphere).
This species’ habitat figures, and what two fixed rules read from them.
The rain rule reads no season: 70% of the year's rain (705 mm of 958 mm) takes 8 months, March and May to November. Mean temperature moves 11.2 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to May and September.
Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: 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 gives a season to reverse. A reading of the curves, not an observation of the plant.
Rain Habitat rain 958 mm a year, wettest June at 112 mm, driest January at 57 mm (habitat calendar, northern hemisphere).
This species’ habitat figures, with their source.
958 mm a year at the habitat, 705 mm of it March and May to November. Wettest month June at 112 mm, driest January at 57 mm. Across the envelope cells the year's total runs 572 mm to 1633 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, northern hemisphere).
CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.
Light Open sky over the habitat: 22 to 40 mol/m²/day.
This species’ habitat figures, with their source.
Open sky over the habitat: 22 to 40 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 16, the highest 90th-percentile month 44).
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.
Warmth and air Cold floor 12 °C (archetype minimum for a tropical foliage plant, above the 4.3 °C habitat night).
This species’ habitat figures, with their source.
Coldest: the 1st-percentile night over 44 years at the typical cell is 4.3 °C, the absolute minimum 0.0 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 40.5 °C. Monthly means: coldest night 11.8 °C in January (across the envelope cells 1.8 °C to 23.1 °C), warmest day 30.6 °C in July (median year across the envelope cells, CHELSA). Cold floor: 12 °C. The habitat figure, the 1st-percentile night over 44 years at the typical cell (NASA POWER), is 4.3 °C; the archetype table's conventional minimum for a tropical foliage plant (grouped by Commelinaceae, which is usually but not always one kind of plant) is 12 °C, which is higher, and the floor rule takes the higher.
NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence, and the archetype table's group minimum where that is higher. Not a measured survival limit for any plant in a pot.
Relative humidity at the habitat: 58 to 61% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.
CHELSA relative humidity, median year across the envelope cells.
The figures the cards read from are in Climate below, and where they came from in Natural habitat.
Climate across the habitat
Figures by month
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 21 / 13–31 | 23 / 15–31 | 24 / 19–31 | 26 / 22–31 | 29 / 22–32 | 30 / 21–33 | 31 / 21–34 | 31 / 23–35 | 29 / 24–32 | 27 / 22–30 | 24 / 18–30 | 22 / 13–30 |
| Night °C | 12 / 2–23 | 13 / 3–23 | 15 / 7–24 | 16 / 11–24 | 19 / 12–24 | 22 / 12–25 | 23 / 12–25 | 23 / 13–25 | 21 / 13–25 | 17 / 12–24 | 15 / 7–23 | 13 / 3–23 |
| Rain mm | 57 / 14–142 | 63 / 13–138 | 76 / 15–147 | 70 / 21–125 | 95 / 24–153 | 112 / 22–227 | 80 / 28–209 | 74 / 30–224 | 92 / 40–232 | 104 / 38–169 | 72 / 18–150 | 63 / 15–154 |
| DLI | 24 / 18–41 | 29 / 22–40 | 33 / 28–41 | 36 / 28–44 | 38 / 24–44 | 39 / 22–43 | 40 / 23–44 | 37 / 26–41 | 33 / 29–38 | 29 / 25–37 | 25 / 19–41 | 22 / 16–41 |
| RH % | 58 / 53–64 | 58 / 52–64 | 58 / 52–64 | 58 / 51–65 | 60 / 53–66 | 61 / 54–67 | 60 / 53–67 | 59 / 52–67 | 59 / 53–67 | 58 / 54–66 | 58 / 53–65 | 58 / 53–65 |
Each figure is the median across the 1549 grid cells holding the 1832 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 1259:1352 (27.025, -112.375). Over 44 years there: absolute minimum 0.0 °C, 1st-percentile night 4.3 °C, 99th-percentile day 40.5 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 1549 distinct grid cells holding the 1832 in-range records; extremes and elevation at the typical cell 1259:1352 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 27.00_-112.500, lapse-corrected +133 m at 6.5 °C/km. Elevation: ETOPO 2022, 616 m (cell mean).
Natural habitat
Photographs
Photographs: (c) Catherine C. Galley, some rights reserved (CC BY) (2); no rights reserved · CC0 (3); (c) Linda Jo Conn, some rights reserved (CC BY); (c) Nicolas Olejnik, some rights reserved (CC BY) (2).
Photographs: iNaturalist and Wikimedia Commons did not answer when this page was built; what is shown came from the sources that did.
Papers naming this species
Works whose title or abstract names Commelina erecta, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.
Related
Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.
Portulaca umbraticola Wingpod Purslane
Malvaviscus arboreus Turk's cap
Portulaca pilosa Kiss me quick
Galphimia gracilis Slender Goldshower
Rivina humilis Baby Pepper
Tradescantia pallida "Wandering Jew"Other Commelina 1 in the reference
History & registers
Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)gbif.synonyms answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)gbif.vernacular answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)wcvp.distribution answeredgbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zamclimate answeredwikidata answeredcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)wikipedia answeredcarried from build of 2026-09-20; this build: skippedinat.taxon not askedcarried from build of 2026-09-20 (rederive)inat.photos.wild answeredcarried from build of 2026-09-20; this build: skippedinat.photos.cultivated nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)commons not askedcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)gbif.media answeredopenalex answeredcarried from build of 2026-09-20; this build: skippedEvery upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 195 datasets via GBIF.org; each carries its own licence.








