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Stuckenia pectinata; photograph author not stated, no rights reserved CC0author not stated, no rights reserved · observed growing wild · 2026-09-12

Stuckenia pectinata (L.) Börner

Sago pondweed; Fennel Pondweed; Fennel-leaved pondweed; Comb pondweed

Potamogetonaceae · Denmark, Finland +209

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Stuckenia pectinata, photograph (c) Arthur Whiting, some rights reserved (CC BY)Stuckenia pectinata, photograph (c) Arthur Whiting, some rights reserved (CC BY)Stuckenia pectinata, photograph (c) Flavien Saboureau, some rights reserved (CC BY)Stuckenia pectinata, photograph (c) Stanislav Murashkin, some rights reserved (CC BY)Stuckenia pectinata, photograph author not stated, no rights reservedStuckenia pectinata, photograph author not stated, no rights reserved 70 photographs ›
Habitat figures
Cold floor (1 night in 100)
-13.1°C
Record low -26.9 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
23°C
Jul at the habitat CHELSA
Rain a year (median across the range)
732mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
4–36DLI
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

Stuckenia pectinata (syn. Potamogeton pectinatus), commonly called sago pondweed or fennel pondweed, and sometimes called ribbon weed, is a cosmopolitan water plant species that grows in fresh and brackish water on all continents except Antarctica.

Quoted from Wikipedia, "Stuckenia pectinata", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (550 mm of 742 mm) takes 8 months, May to December. Mean temperature moves 19.3 °C between the warmest and coldest month. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to June.

Rain

742 mm in the median year at the habitat, 550 mm of it May to December. Wettest month July at 78 mm, driest month February at 43 mm. Across the grid cells of the range the year's total runs 536 mm to 1,154 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 732 mm, is the year's rain at the top of the page; the 742 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: 4 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 2, 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 -13.1 °C, the absolute minimum -26.9 °C, 4,286 frost nights in 44 years, 97.4 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 35.2 °C. Monthly means: the coldest month's mean nightly low -3.3 °C in January (across the grid cells of the range -12.1 °C to 1.8 °C), the warmest month's mean daily high 23.0 °C in July (median year across the grid cells of the range, CHELSA). Cold floor: -13.1 °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: 58 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 -30 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 Stuckenia pectinata through the yearWarmest month July, mean daily high 23 °C; coldest month January, mean nightly low -3.3 °C; 742 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°frost35.2° 99th-percentile day, NASA POWER-26.9° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0255075100125mm rainDLI 4–36RH 58–68%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 492 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 °C2 / -6–74 / -5–88 / 0–1113 / 8–1618 / 13–2121 / 16–2523 / 19–2722 / 19–2718 / 14–2214 / 8–178 / 0–113 / -4–7
Night °C-3 / -12–2-3 / -12–20 / -7–44 / 0–69 / 6–1112 / 10–1515 / 13–1814 / 13–1811 / 8–147 / 2–102 / -4–5-2 / -10–3
Rain mm54 / 30–8543 / 28–7750 / 32–8645 / 31–9063 / 39–11373 / 51–11778 / 54–11674 / 45–11167 / 46–10571 / 37–10764 / 40–10060 / 37–104
DLI6 / 3–1211 / 7–1819 / 15–2628 / 26–3334 / 32–3836 / 33–4135 / 32–4029 / 26–3520 / 16–2712 / 8–196 / 3–124 / 2–10
RH %67 / 62–7265 / 60–6962 / 58–6559 / 56–6158 / 55–6159 / 56–6259 / 56–6260 / 56–6262 / 58–6464 / 59–6667 / 61–6968 / 62–71
How this section is made
Each figure is the median across the 492 grid cells on land that hold in-range records (569 records in those cells; 41 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 840:3941 (47.975, 17.075). Over 44 years there: absolute minimum -26.9 °C, 1st-percentile night -13.1 °C, 99th-percentile day 35.2 °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 492 distinct grid cells holding 569 of the 645 in-range records (41 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 840:3941 (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 48.00_16.875, lapse-corrected -30 m at 6.5 °C/km. Elevation: ETOPO 2022, 132 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.
NativeDenmark, Finland, Great Britain, Ireland, Norway, Sweden, Austria, Belgium, Czechoslovakia, Germany, Hungary, Netherlands, Poland, Switzerland, Baleares, Corse, France, Portugal, Sardegna, Spain, Albania, Bulgaria, Greece, Italy, Kriti, Romania, Sicilia, Turkey-in-Europe, Yugoslavia, Belarus, Baltic States, Krym, Central European Russia, East European Russia, North European Russia, South European Russia, Northwest European Russia, Ukraine, Algeria, Egypt, Libya, Morocco, Tunisia, Mauritania, Burundi, Rwanda, Zaïre, Eritrea, Ethiopia, Socotra, Sudan, Kenya, Tanzania, Uganda, Angola, Malawi, Mozambique, Zambia, Zimbabwe, Botswana, Cape Provinces, Caprivi Strip, Namibia, KwaZulu-Natal, Free State, Northern Provinces, Mauritius, Madagascar, Réunion, Altay, Buryatiya, Chita, Irkutsk, Krasnoyarsk, Tuva, West Siberia, Yakutskiya, Amur, Kamchatka, Kuril Is., Magadan, Primorye, Sakhalin, Kazakhstan, Kirgizistan, Turkmenistan, Tadzhikistan, Uzbekistan, North Caucasus, Transcaucasus, Afghanistan, Cyprus, Iran, Iraq, Lebanon-Syria, Palestine, Sinai, Turkey, Gulf States, Oman, Saudi Arabia, Yemen, China South-Central, Hainan, Inner Mongolia, Manchuria, China North-Central, Qinghai, China Southeast, Tibet, Xinjiang, Mongolia, Japan, Korea, Nansei-shoto, Taiwan, Assam, Bangladesh, India, Nepal, Pakistan, Sri Lanka, West Himalaya, Myanmar, Lesser Sunda Is., Philippines, Sulawesi, Sumatera, Solomon Is., New Zealand North, New Zealand South, New Caledonia, Vanuatu, Aleutian Is., Alaska, Northwest Territories, Yukon, Alberta, British Columbia, Manitoba, Saskatchewan, New Brunswick, Newfoundland, 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, Nevada, Utah, New Mexico, Texas, Alabama, Arkansas, Florida, Kentucky, Louisiana, Maryland, North Carolina, Tennessee, Virginia, Mexico Central, Mexico Northeast, Mexico Gulf, Mexico Northwest, Mexico Southwest, Mexico Southeast, Belize, C. American Pacific Is., El Salvador, Guatemala, Panama, Cuba, Haiti, Venezuela, Bolivia, Colombia, Ecuador, Galápagos, Peru, Chile Central · introduced: Hawaii · 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 marker51.439, 4.765 · in the densest population, 225 records (34% of those in range)
Kew's description“rhizomatous hydrogeophyte” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 659 georeferenced records inside the native range; the climate across the range on the 569 of them in the land cells it reads, of 645 placed to within 10 km; the map shows only the 287 openly licensed ones, which alone would put the marker 1455 km away. 3 records outside the WCVP native range not used. 14 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 659 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Stuckenia pectinata, photograph 1did not loadStuckenia pectinata, photograph 2did not loadStuckenia pectinata, photograph 3did not loadStuckenia pectinata, photograph 4did not loadStuckenia pectinata, photograph 5did not loadStuckenia pectinata, photograph 6did not load

Photographs: (c) Arthur Whiting, some rights reserved (CC BY) (2); (c) Flavien Saboureau, some rights reserved (CC BY); (c) Stanislav Murashkin, 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.

Ulmus laevis Ulmus laevis European white elm Photo: CC0, author not statedCarex bohemica Carex bohemica Bohemian Sedge Photo: CC BY, Дарья ДрущенкоTypha angustifolia Typha angustifolia Lesser bulrush Photo: CC BY, Tanner BarnharstThlaspi arvense Thlaspi arvense Field pennycress Photo: CC BY, Bobo-XDelphinium consolida Delphinium consolida Forking larkspur Photo: CC BY-SA, Baselga PabloPlantago media Plantago media Hoary plantain Photo: CC0, author not stated

Names & registers

Also known as Buccaferrea pectinata; Coleogeton pectinatus; Coleogeton pectinatus subsp. balatonicus; Potamogeton acifolius; Potamogeton angustifolius f. longipedunculatus and 114 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Potamogetonaceae
Described by
(L.) Börner
Native to
Denmark, Finland, Great Britain +208
Wild records
659 in range · 287 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 answeredasked 2026-10-22GBIF occurrence search API; 12 records within 1 km of a botanic garden, herbarium or zoo left out (6 at a botanic garden or arboretum, 1 at a herbarium, 5 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 48.00_16.875, lapse-corrected -30 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by its label; its IPNI identifier 77099639-1 is Kew's for Stuckenia pectinata (L.) Börner
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 14 datasets via GBIF.org; each carries its own licence.

Cultifolio

Opening your plants…