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Sagittaria guayanensis; photograph author not stated, no rights reserved CC0author not stated, no rights reserved · observed growing wild · 2024-05-25

Sagittaria guayanensis Kunth

Guyanese arrowhead; Arrowhead; Arrowhead-lily; Swamp-potato

Alismataceae · Burkina, The Gambia +61

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Sagittaria guayanensis, photograph (c) Non_Praying_Mantis, some rights reserved (CC BY)Sagittaria guayanensis, photograph (c) Brenda O'Grady, some rights reserved (CC BY-SA)Sagittaria guayanensis, photograph (c) Brenda O'Grady, some rights reserved (CC BY-SA)Sagittaria guayanensis, photograph (c) Brenda O'Grady, some rights reserved (CC BY-SA)Sagittaria guayanensis, photograph author not stated, no rights reservedSagittaria guayanensis, photograph author not stated, no rights reserved 38 photographs ›
Habitat figures
Cold floor (1 night in 100)
19.7°C
Record low 16.8 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
32°C
Mar at the habitat CHELSA
Rain a year (median across the range)
1,940mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
30–36DLI
Lowest to highest month (DLI) CHELSA
The year in the habitat's months, not shifted
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
A sharp rainy season, April to September (the habitat's months, not shifted), in a year of even temperature. rain rule, CHELSA
Not shifted: the shift rule does not apply to this habitat. The chart is in the habitat's months.

Summary

Sagittaria guayanensis, the Guyanese arrowhead, is a perennial aquatic plant species native to both the Old and New World. It has broadly hastate (arrow-shaped) leaves with ovate lobes.

Quoted from Wikipedia, "Sagittaria guayanensis", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a sharp season: 70% of the median year's rain (1,387 mm of 1,899 mm) falls in April to September. The temperature curve is flat, 1.2 °C between the warmest and coldest month, so the growing-season rule does not infer a growing season from it. Months are the habitat's, northern hemisphere. The habitat lies within 10° of the equator, where the shift rule does not apply, so they are not shifted for a collection elsewhere.

Rain

1,899 mm in the median year at the habitat, 1,387 mm of it April to September. Wettest month August at 260 mm, driest month January at 28 mm. Across the grid cells of the range the year's total runs 977 mm to 3,200 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,940 mm, is the year's rain at the top of the page; the 1,899 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: 30 to 36 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 24, the highest 90th-percentile month 46).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 19.7 °C, the absolute minimum 16.8 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.7 °C. Monthly means: the coldest month's mean nightly low 22.5 °C in January (across the grid cells of the range 14.6 °C to 23.7 °C), the warmest month's mean daily high 31.6 °C in March (median year across the grid cells of the range, CHELSA). Cold floor: 19.7 °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 68% 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 +1 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 Sagittaria guayanensis through the yearWarmest month March, mean daily high 32 °C; coldest month January, mean nightly low 22.5 °C; 1,899 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°15°20°25°30°35°40°37.7° 99th-percentile day, NASA POWER16.8° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 30–36RH 57–68%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 126 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 °C30 / 26–3331 / 27–3432 / 28–3630 / 28–3829 / 28–3729 / 27–3529 / 27–3230 / 28–3230 / 29–3230 / 28–3330 / 27–3430 / 26–32
Night °C23 / 15–2423 / 16–2423 / 18–2423 / 20–2523 / 21–2623 / 21–2523 / 21–2523 / 21–2523 / 21–2523 / 20–2423 / 18–2423 / 16–24
Rain mm28 / 1–26143 / 1–23669 / 2–258188 / 4–386211 / 30–451251 / 99–424232 / 112–388260 / 90–355245 / 61–350186 / 38–328125 / 4–24261 / 1–205
DLI33 / 27–3735 / 29–4036 / 31–4433 / 29–4630 / 26–4531 / 24–3933 / 25–3933 / 28–3933 / 30–4032 / 29–3931 / 27–3831 / 26–35
RH %58 / 39–6757 / 38–6758 / 41–6664 / 45–6967 / 51–7068 / 57–7167 / 60–7067 / 61–6967 / 62–7066 / 57–6965 / 47–6962 / 41–68

Records on both sides of the equator: the 21 cells at least 10° south of it have seasons six months apart and are left out, not combined into a year no place has. These figures are across the 126 cells that remain: the 51 at least 10° north and the 75 within 10° of the equator, which stay in either way.

How this section is made
Each figure is the median across the 126 grid cells on land that hold in-range records (150 records in those cells; 1 more cell holds records but no land by the elevation layer, so those records sit at sea and the cell is 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 1710:2172 (4.475, -71.375). Over 44 years there: absolute minimum 16.8 °C, 1st-percentile night 19.7 °C, 99th-percentile day 37.7 °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 126 distinct grid cells holding 150 of the 175 in-range records (1 further cell with records at sea, by the elevation layer, left out) on the northern side of the equator (51 cells poleward of 10° north, 21 poleward of 10° south: the two sides' seasons are not combined, and cells within 10° of the equator stay in); extremes and elevation at the typical cell 1710:2172 (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 4.50_-71.250, lapse-corrected +1 m at 6.5 °C/km. Elevation: ETOPO 2022, 160 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.
NativeBurkina, The Gambia, Ghana, Guinea-Bissau, Ivory Coast, Mali, Nigeria, Niger, Senegal, Cameroon, Chad, Sudan, Madagascar, Afghanistan, China South-Central, Hainan, China Southeast, Taiwan, Assam, Bangladesh, East Himalaya, India, Nepal, Pakistan, West Himalaya, Cambodia, Laos, Myanmar, Thailand, Vietnam, Jawa, Malaya, Sulawesi, Sumatera, Mexico Central, Mexico Gulf, Mexico Southwest, Mexico Southeast, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Cuba, Dominican Republic, Jamaica, Trinidad-Tobago, French Guiana, Guyana, Surinam, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil North, Argentina Northeast, Paraguay, Uruguay · introduced: Louisiana · 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 marker4.894, -71.431 · in the densest population, 108 records (14% of those in range)
Kew's description“hydroannual or tuberous geophyte” · “wet tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 769 georeferenced records inside the native range; the climate across the range on the 150 of them in the land cells it reads, of 175 placed to within 10 km; the map shows only the 602 openly licensed ones, which alone would put the marker 3099 km away. 8 records outside the WCVP native range not used. 594 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 769 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Sagittaria guayanensis, photograph 1did not loadSagittaria guayanensis, photograph 2did not loadSagittaria guayanensis, photograph 3did not loadSagittaria guayanensis, photograph 4did not loadSagittaria guayanensis, photograph 5did not loadSagittaria guayanensis, photograph 6did not load

Photographs: (c) Non_Praying_Mantis, some rights reserved (CC BY); (c) Brenda O'Grady, some rights reserved (CC BY-SA) (3); 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.

Spondias mombin Spondias mombin Hog plum Photo: CC0, author not statedHandroanthus chrysanthus Handroanthus chrysanthus Roble amarillo Photo: CC BY, Francisco Farriols SarabiaSapium glandulosum Sapium glandulosum Gumtree Photo: CC BY, Guillaume DelaitreRosenbergiodendron formosum Rosenbergiodendron formosum Rubiaceae Photo: CC BY, Matteo BellucciCavanillesia platanifolia Cavanillesia platanifolia Canoe tree Photo: CC BY, Anthony BatistaAttalea butyracea Attalea butyracea Kuakish Photo: CC BY, Erick Vélez Sánchez

Other Sagittaria 18 in the reference

Sagittaria calycina Sagittaria calycina Alismataceae Photo: CC BY, Dan JohnsonSagittaria cuneata Sagittaria cuneata Northern arrowhead Photo: CC BY, Arthur WhitingSagittaria filiformis Sagittaria filiformis Threadleaf arrowhead Photo: CC BY, Patrick BelkSagittaria graminea Sagittaria graminea Grass-leaved arrowhead Photo: CC BY, Patrick JacksonSagittaria intermedia Sagittaria intermedia Intermediate arrowhead Photo: CC BY, PatrickSagittaria lancifolia Sagittaria lancifolia Bulltongue Photo: CC0, author not statedSagittaria latifolia Sagittaria latifolia Duck-potato Photo: CC BY, Mandatory WalkSagittaria longiloba Sagittaria longiloba Longbarb arrowhead Photo: CC BY, Claudio Cantú Muñiz Sagittaria macrophylla Alismataceae Sagittaria montevidensis Sagittaria montevidensis Giant arrowhead Photo: CC BY, Pablo H CapovillaSagittaria natans Sagittaria natans Floating arrowhead Photo: CC BY, Valerii GlazunovSagittaria platyphylla Sagittaria platyphylla Delta arrowhead Photo: CC BY, Jay Pruett all 19 ›

Names & registers

Also known as Echinodorus guayanensis; Echinodorus guianensis; Lophiocarpus guayanensis; Lophotocarpus guayanensis; Lophotocarpus guayanensis var. typicus. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Alismataceae
Described by
Kunth
Native to
Burkina, The Gambia, Ghana +60
Wild records
769 in range · 602 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; 2 records within 1 km of a botanic garden, herbarium or zoo left out (2 at a botanic garden or arboretum; 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 4.50_-71.250, lapse-corrected +1 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22IPNI and POWO linked by Kew's number for Sagittaria guayanensis Kunth (the item's: IPNI 225261-2, POWO 58497-1)
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 144 datasets via GBIF.org; each carries its own licence.

Cultifolio

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