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Sisyrinchium bermudiana; photograph author not stated, no rights reserved CC0author not stated, no rights reserved · observed growing wild · 2026-04-24

Sisyrinchium bermudiana L.

Blue-eyed-grass; Bermudiana; Bermuda Blue-eyed Grass

Iridaceae · Bermuda

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Sisyrinchium bermudiana, photograph author not stated, no rights reservedSisyrinchium bermudiana, photograph author not stated, no rights reservedSisyrinchium bermudiana, photograph author not stated, no rights reservedSisyrinchium bermudiana, photograph author not stated, no rights reservedSisyrinchium bermudiana, photograph author not stated, no rights reservedSisyrinchium bermudiana, photograph author not stated, no rights reserved 49 photographs ›
Habitat figures
Coldest month, mean nightly low
16.6°C
Feb at the habitat, not a floor; extremes not used (sea cell) CHELSA
Warmest month, mean daily high
27°C
Aug at the habitat CHELSA
Rain a year (median across the range)
1,614mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
15–42DLI
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 8 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

Sisyrinchium bermudiana, known as Bermudiana or, along with other members of the genus, as blue-eyed grass, is a flower of the genus Sisyrinchium (of the Iris family) that is native to the Atlantic archipelago, and British Overseas Territory, of Bermuda and the island of Ireland. The plant appears and blooms in the spring. It is used as a national flower by Bermudians, and appears in art, jewellery, banknotes and elsewhere.

Quoted from Wikipedia, "Sisyrinchium bermudiana", CC BY-SA 4.0.

About the genus · Sisyrinchium

Sisyrinchium is a large genus of annual to perennial flowering plants in the family Iridaceae. Native to the New World, the species are known as blue-eyed grasses. Although they are not true grasses (Poaceae), they are monocots.

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

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (1,159 mm of 1,614 mm) takes 8 months, December to March and July to October. Mean temperature moves 8.6 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: January to April and June to September.

Rain

1,614 mm in the median year at the habitat, 1,159 mm of it December to March and July to October. Wettest month October at 177 mm, driest month November at 111 mm. Across the grid cells of the range the year's total runs 1,588 mm to 1,623 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,614 mm, is the year's rain at the top of the page; the 1,614 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 42 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low 16.6 °C in February (across the grid cells of the range 16.6 °C to 16.6 °C), the warmest month's mean daily high 27.0 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 16.6 °C, the coldest month's mean nightly low, February, 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 that is mostly sea and are not used.

Humidity

Relative humidity at the habitat: 57 to 67% 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 Sisyrinchium bermudiana through the yearWarmest month August, mean daily high 27 °C; coldest month February, mean nightly low 16.6 °C; 1,614 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, northern hemisphere.15°20°25°30°°C · day and nightcold quarter050100150200mm rainDLI 15–42RH 57–67%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 7 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 °C1919 / 19–1919 / 19–1920222426 / 26–2727 / 27–272625 / 25–252221 / 21–21
Night °C171717 / 17–17182023 / 23–232525 / 25–2625 / 25–252321 / 21–2118 / 18–19
Rain mm140 / 137–141128 / 126–128129 / 127–129117 / 115–117112 / 110–112115 / 113–116132 / 130–133171 / 168–172155 / 153–156177 / 175–178111 / 110–112127 / 125–128
DLI1621 / 21–2129 / 28–2937 / 36–374141423933 / 33–332418 / 18–1815
RH %57585859 / 59–60646766646259 / 59–605757

The daily extremes were read at a NASA POWER cell that is 0% land: neither it nor the next candidates whose coldest month's mean nightly low is within 2 °C of the median across cells sit in a POWER cell that is mostly land, and the rule reads a cold floor only from a cell that is mostly land, so none is read for this species. Nor is the coldest month's mean nightly low taken as one: it is a mean of a month's lows, not its coldest night. What that cell gave over 44 years: absolute minimum 11.1 °C, 1st-percentile night 14.0 °C, 99th-percentile day 28.6 °C.

How this section is made
Each figure is the median across the 7 grid cells on land that hold in-range records (46 records in those cells; 4 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 1152:2306 (32.375, -64.675). 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 7 distinct grid cells holding 46 of the 56 in-range records (4 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1152:2306 (its coldest month's mean nightly low nearest the median across cells, though its NASA POWER cell is only 0% land and none of the 6 next candidates within 2 °C of the median was mostly land); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 32.50_-64.375, lapse-corrected +2 m at 6.5 °C/km. Elevation: ETOPO 2022, 2 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.
NativeBermuda · 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 marker32.315, -64.746 · in the densest population, 61 records (100% of those in range)
Kew's description“perennial” · “subtropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 61 georeferenced records inside the native range; the climate across the range on the 46 of them in the land cells it reads, of 56 placed to within 10 km; the map shows only the 14 openly licensed ones, which alone would put the marker 2 km away. 528 records outside the WCVP native range not used. 5 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 61 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Sisyrinchium bermudiana, photograph 1did not loadSisyrinchium bermudiana, photograph 2did not loadSisyrinchium bermudiana, photograph 3did not loadSisyrinchium bermudiana, photograph 4did not loadSisyrinchium bermudiana, photograph 5did not loadSisyrinchium bermudiana, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0 (6).

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

Juniperus bermudiana Juniperus bermudiana Bermuda cedar Photo: CC BY, Kevin FaccendaHibiscus glaber Hibiscus glaber Malvaceae Photo: CC BY, M108tLigustrum liukiuense Ligustrum liukiuense Oleaceae Photo: CC BY, 謝麗霦Vitex rotundifolia Vitex rotundifolia Round-leaf chastetree Photo: CC BY, Tyler EkholmPinus luchuensis Pinus luchuensis Luchu pine Photo: CC BY, rjtizardCirsium brevicaule Cirsium brevicaule Okinawa Thistle Photo: CC0, author not stated

Other Sisyrinchium 25 in the reference

Sisyrinchium albidum Sisyrinchium albidum White blue-eyed grass Photo: CC0, author not statedSisyrinchium angustifolium Sisyrinchium angustifolium Narrow-leaf blue-eyed-grass Photo: CC BY, Matt PelikanSisyrinchium arenarium Sisyrinchium arenarium Iridaceae Photo: CC BY-SA, Grzegorz GrzejszczakSisyrinchium atlanticum Sisyrinchium atlanticum Eastern blue-eyed grass Photo: CC0, author not statedSisyrinchium bellum Sisyrinchium bellum Western blue-eyed grass Photo: CC BY-SA, paulexcoffSisyrinchium californicum Sisyrinchium californicum Yellow-eyed-grass Photo: CC BY, Alexis Tinker-TsavalasSisyrinchium campestre Sisyrinchium campestre Prairie blue-eyed grass Photo: CC BY, Bria Abeles-AllisonSisyrinchium chilense Sisyrinchium chilense Swordleaf blue-eyed grass Photo: CC BY, Lucas CarboneSisyrinchium convolutum Sisyrinchium convolutum Iridaceae Photo: CC BY, Anders HastingsSisyrinchium demissum Sisyrinchium demissum Stiff blue-eyed grass Photo: CC BY, Abraham Sánchez RomeroSisyrinchium ensigerum Sisyrinchium ensigerum Swordleaf blue-eyed grass Photo: CC BY, IDClaireSisyrinchium graminifolium Sisyrinchium graminifolium Iridaceae Photo: CC BY, Gaston Carvallo B. all 26 ›

Names & registers

Also known as Bermudiana bermudiana; Marica bermudiana; Moraea bermudiana; Sisyrynchium angustifolium; Sisyrynchium bermudiana. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Iridaceae
Described by
L.
Native to
Bermuda
Wild records
61 in range · 14 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; 19 records within 1 km of a botanic garden, herbarium or zoo left out (11 at a botanic garden or arboretum, 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 32.50_-64.375, lapse-corrected +2 m at 6.5 °C/km; read, and set aside: NASA POWER's cell is mostly sea (0% land), so no cold floor is shown
Wikidata wikidata answeredasked 2026-10-22IPNI and POWO linked by Kew's number for Sisyrinchium bermudiana L. (the item's: IPNI 440951-1, POWO 440950-1)
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 72 datasets via GBIF.org; each carries its own licence.

Cultifolio

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