Species
+

Hibiscus trionum L.

Bladder Ketmia, Bladder ketmia, Flower-of-an-hour, Flower of an hour, Venice mallow

Climate known 69 photographs
Add one to my plants Sow seed

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

Hibiscus trionum, commonly called flower-of-an-hour, bladder hibiscus, bladder ketmia, bladder weed, puarangi and venice mallow, is an annual plant native to the Old World tropics and subtropics. It has spread throughout southern Europe both as a weed and cultivated as a garden plant. It has been introduced to the United States as an ornamental where it has become naturalized as a weed of cropland and vacant land, particularly on disturbed ground.

Text from Wikipedia, “Hibiscus trionum”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Hibiscus

Hibiscus is a genus of plants in the family Malvaceae native to the tropics and subtropics. The genus is quite large, comprising 319 species. Hibiscus are renowned for their large, showy flowers and those species are commonly known simply as "hibiscus", or less widely known as rose mallow. More on Wikipedia ›

The opening of Wikipedia, “Hibiscus”, CC BY-SA 4.0, quoted as written.

Family
Malvaceae
Described by
L.
Native to
Czechoslovakia, Hungary, Poland +30
Wild records
307 in range· 210 open

At a glance

Warmest month
27°C
Jul, mean day; nights 17 °C (CHELSA)
Rain
634mm/yr
12 wet months · peak Jun 75 mm (CHELSA)
Light
7–38DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Rain rule: no season, 70% of the rain takes 8 months (April to September and November to December in the northern hemisphere). Habitat rain 634 mm a year, wettest June at 75 mm, driest February at 35 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 7 to 38 mol/m²/day. Cold floor -12.8 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Abelmoschus collinsianus (Nutt. ex Torr. & A.Gray) Alph.Wood; Hibiscus africanus Mill.; Hibiscus armeniacus Bouché; Hibiscus collinsianus Nutt.; Hibiscus collinsianus Nutt. ex Torr. & A.Gray and 31 more.

Cultivation

Its year Rain rule: no season, 70% of the rain takes 8 months (April to September and November to December 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 (472 mm of 634 mm) takes 8 months, April to September and November to December. Mean temperature moves 22.3 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: October to March and May to June.

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 634 mm a year, wettest June at 75 mm, driest February at 35 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

634 mm a year at the habitat, 472 mm of it April to September and November to December. Wettest month June at 75 mm, driest February at 35 mm. Across the envelope cells the year's total runs 525 mm to 1105 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: 7 to 38 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 7 to 38 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 6, the highest 90th-percentile month 46).

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 -12.8 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is -12.8 °C, the absolute minimum -27.9 °C, about 96 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 35.3 °C. Monthly means: coldest night -3.5 °C in January (across the envelope cells -6.1 °C to 2.7 °C), warmest day 26.6 °C in July (median year across the envelope cells, CHELSA). Cold floor: -12.8 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

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. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 56 to 66% 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

Habitat climate through the yearMean day from 3 °C in Jan to 27 °C in Jul; mean night from -4 °C in Jan to 17 °C in Jul. The cold quarter, Dec to Feb, is the three months around the coldest night. 634 mm of rain a year, most in Jun. The bands show the 10th to 90th percentile across 286 habitat cells. Over 44 years at the typical cell the absolute minimum was -27.9 °C and the 99th-percentile day 35.3 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-40°-20°20°40°frost35.3° 99th-percentile day (undated)-27.9° lowest night in 44 yrs (undated)°C · day and nightcold quarter0255075100125mm rainDLI 7–38RH 56–66 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 286 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C3 / 1–105 / 3–1110 / 7–1416 / 13–1721 / 19–2324 / 22–2627 / 24–3026 / 24–2921 / 19–2516 / 14–209 / 7–144 / 2–10
Night °C-4 / -6–3-3 / -6–31 / -1–66 / 4–811 / 9–1315 / 12–1717 / 14–2017 / 14–2012 / 10–168 / 5–122 / 0–7-2 / -4–4
Rain mm39 / 28–8435 / 28–7942 / 32–8249 / 37–9264 / 41–10075 / 29–10664 / 16–9662 / 24–9655 / 41–11446 / 36–12052 / 38–11951 / 37–108
DLI9 / 7–1415 / 12–2022 / 20–2931 / 28–3636 / 35–4238 / 36–4638 / 35–4634 / 30–4025 / 22–3216 / 14–2310 / 8–157 / 6–12
RH %65 / 60–6862 / 58–6459 / 57–6257 / 55–6057 / 55–6057 / 54–6056 / 52–5956 / 53–6058 / 56–6161 / 59–6464 / 59–6766 / 60–68

Each figure is the median across the 286 grid cells holding the 300 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 859:3964 (47.025, 18.225). Over 44 years there: absolute minimum -27.9 °C, 1st-percentile night -12.8 °C, 99th-percentile day 35.3 °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 286 distinct grid cells holding the 300 in-range records; extremes and elevation at the typical cell 859:3964 (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 47.00_18.125, lapse-corrected -43 m at 6.5 °C/km. Elevation: ETOPO 2022, 141 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 every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeCzechoslovakia, Hungary, Poland, Portugal, Spain, Albania, Bulgaria, Greece, Italy, Kriti, Romania, Sicilia, Turkey-in-Europe, Yugoslavia, Krym, South European Russia, Ukraine, Algeria, Libya, Morocco, Tunisia, North Caucasus, Transcaucasus, Afghanistan, Cyprus, Iran, Iraq, Lebanon-Syria, Palestine, Turkey, India, Pakistan, West Himalaya· introduced: Great Britain, Austria, Belgium, Germany, France, Baltic States, Canary Is., Mauritius, Chita, Irkutsk, West Siberia, Amur, Primorye, Kazakhstan, Kirgizistan, Turkmenistan, Tadzhikistan, Uzbekistan, China South-Central, Hainan, Inner Mongolia, Manchuria, China North-Central, China Southeast, Tibet, Xinjiang, Mongolia, Japan, Korea, Taiwan, Assam, Bangladesh, Myanmar, New Zealand North, New Zealand South, New Caledonia, Manitoba, Saskatchewan, New Brunswick, Nova Scotia, Ontario, Prince Edward I., Québec, Colorado, Idaho, Montana, Oregon, Washington, Wyoming, Illinois, Iowa, Kansas, Minnesota, Missouri, North Dakota, Nebraska, Oklahoma, South Dakota, Wisconsin, Connecticut, Indiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode I., Vermont, West Virginia, Arizona, California, Utah, New Mexico, Texas, Alabama, Arkansas, Delaware, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, District of Columbia, Cuba, Jamaica, Chile Central, Uruguay
Kew's description“annual or biennial” · “subtropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker47.58, 19.378 · in the densest population, 63 records (21% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 307 georeferenced records inside the native range; the map shows only the 210 openly licensed ones, which alone would put the marker 9 km away. 1607 records outside the range (gardens, roadsides, misidentifications) ignored. 7 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 307 in-range records; it decides nothing.

Photographs

Hibiscus trionumHibiscus trionumHibiscus trionumHibiscus trionumHibiscus trionumHibiscus trionumHibiscus trionumHibiscus trionum

Photographs: (c) Tony Rebelo, some rights reserved (CC BY-SA) (3); (c) Thomas Koffel, some rights reserved (CC BY) (5).

Photographs: iNaturalist 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 Hibiscus trionum, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Structural coloration in nature
Jiyu Sun, Bharat Bhushan, Jin Tong (2013) · RSC Advances
Floral Iridescence, Produced by Diffractive Optics, Acts As a Cue for Animal Pollinators
Heather M. Whitney, Mathias Kolle, Piers Andrew, Lars Chıttka (2009) · Science
The flower of H ibiscus trionum is both visibly and measurably iridescent
Silvia Vignolini, Edwige Moyroud, Thomas Hingant, Hannah Banks (2014) · New Phytologist
A survey of management and economic impact of weeds in dryland cotton cropping systems of subtropical Australia
S. Walker, Ian Taylor, Gavin Milne, V. A. Osten (2005) · Australian Journal of Experimental Agriculture
Selective regulation of germination and growth of annual weeds by crop residues
C. E. Purvis, R. S. Jessop, J. V. Lovett (1985) · Weed Research
Biomass allocation in hermaphrodite flowers
Jon Lovett Doust, Paul B. Cavers (1982) · Canadian Journal of Botany
Reversible curvature of style branches of Hibiscus trionum L., a pollination mechanism
MS Buttrose, WJR Grant, JNA Lott (1977) · Australian Journal of Botany
Phytotoxic effects of Echinochloa colona (L.) Link. (Poaceae) extracts on the germination and seedling growth of weeds
Nasr H. Gomaa, Hamada AbdElgawad (2012) · Spanish Journal of Agricultural Research
Dissecting molecular mechanisms underlying the inhibition of β-glucuronidase by alkaloids from Hibiscus trionum: Integrating in vitro and in silico perspectives
Emadeldin M. Kamel, Faris F. Aba Alkhayl, Haifa A. Alqhtani, May Bin‐Jumah (2024) · Computers in Biology and Medicine
Bridging in silico and in vitro perspectives to unravel molecular mechanisms underlying the inhibition of β-glucuronidase by coumarins from Hibiscus trionum
Emadeldin M. Kamel, Faris F. Aba Alkhayl, Haifa A. Alqhtani, May Bin‐Jumah (2024) · Biophysical Chemistry
Contributions of iridescence to floral patterning
Heather M. Whitney, Mathias Kolle, Rubén Álvarez-Fernández, Ullrich Steiner (2009) · Communicative & Integrative Biology

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.

Other Hibiscus 10 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild answeredcarried from build of 2026-09-19; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-19; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 155 datasets via GBIF.org; each carries its own licence.