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Paspalum vaginatum; photograph (c) Cricket Raspet, some rights reserved (CC BY) CC BY(c) Cricket Raspet, some rights reserved (CC BY) · observed growing wild · 2026-07-01

Paspalum vaginatum Sw.

Seashore paspalum; Biscuit grass; Saltwater couch; Silt grass

Poaceae · Texas, Alabama +52

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Paspalum vaginatum, photograph author not stated, no rights reservedPaspalum vaginatum, photograph author not stated, no rights reservedPaspalum vaginatum, photograph author not stated, no rights reservedPaspalum vaginatum, photograph (c) Joe Dillon, some rights reserved (CC BY)Paspalum vaginatum, photograph (c) Joe Dillon, some rights reserved (CC BY)Paspalum vaginatum, photograph (c) Tony Rebelo, some rights reserved (CC BY-SA) 92 photographs ›
Habitat figures
Cold floor (1 night in 100)
11.7°C
Record low 8.3 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
29°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
1,318mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
26–41DLI
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

Paspalum vaginatum is a species of grass known by many names, including seashore paspalum, biscuit grass, saltwater couch, silt grass, and swamp couch. It is native to the Americas, where it grows in tropical and subtropical regions. It is found throughout the other tropical areas of the world, where it is an introduced species and sometimes an invasive weed. It is also cultivated as a turfgrass in many places.

Quoted from Wikipedia, "Paspalum vaginatum", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (954 mm of 1,258 mm) takes 8 months, January and May to November. Mean temperature moves 5.4 °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 July.

Rain

1,258 mm in the median year at the habitat, 954 mm of it January and May to November. Wettest month September at 159 mm, driest months (2 at 73 mm). Across the grid cells of the range the year's total runs 573 mm to 2,391 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,318 mm, is the year's rain at the top of the page; the 1,258 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: 26 to 41 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 17, the highest 90th-percentile month 44).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 11.7 °C, the absolute minimum 8.3 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.9 °C. Monthly means: the coldest month's mean nightly low 18.8 °C in December (across the grid cells of the range 10.1 °C to 24.5 °C), the warmest month's mean daily high 29.0 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: 11.7 °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: 60 to 64% 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 +117 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 Paspalum vaginatum through the yearWarmest months July and August, mean daily high 29 °C; coldest month December, mean nightly low 18.8 °C; 1,258 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.5°10°15°20°25°30°35°40°37.9° 99th-percentile day, NASA POWER8.3° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050100150200250300mm rainDLI 26–41RH 60–64%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 70 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 °C25 / 16–2925 / 18–2926 / 19–3026 / 22–3127 / 21–3228 / 19–3229 / 18–3329 / 19–3328 / 20–3127 / 21–3025 / 21–2925 / 18–28
Night °C19 / 9–2420 / 10–2419 / 12–2421 / 15–2523 / 13–2524 / 15–2624 / 14–2624 / 14–2724 / 14–2623 / 13–2620 / 14–2519 / 10–25
Rain mm81 / 28–22579 / 12–20179 / 8–19673 / 19–19987 / 21–246148 / 25–292142 / 40–229148 / 46–263159 / 36–244105 / 36–22784 / 17–15473 / 20–170
DLI27 / 19–4231 / 24–3935 / 31–4239 / 26–4441 / 20–4439 / 17–4240 / 19–4338 / 24–4133 / 28–3931 / 27–3928 / 21–4226 / 18–44
RH %61 / 56–6661 / 55–6561 / 53–6561 / 52–6662 / 54–6764 / 59–6764 / 59–6664 / 59–6663 / 60–6761 / 58–6661 / 57–6660 / 57–67
How this section is made
Each figure is the median across the 70 grid cells on land that hold in-range records (77 records in those cells; 6 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 1462:1777 (16.875, -91.125). Over 44 years there: absolute minimum 8.3 °C, 1st-percentile night 11.7 °C, 99th-percentile day 37.9 °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 70 distinct grid cells holding 77 of the 83 in-range records (6 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1462:1777 (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 17.00_-91.250, lapse-corrected +117 m at 6.5 °C/km. Elevation: ETOPO 2022, 558 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.
NativeTexas, Alabama, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina, Mexico Central, Mexico Northeast, Mexico Gulf, Mexico Northwest, Mexico Southwest, Mexico Southeast, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Bahamas, Bermuda, Cayman Is., Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is. AB Ant, Puerto Rico, Trinidad-Tobago, Windward Is., French Guiana, Guyana, Surinam, Venezuela, Bolivia, Colombia, Ecuador, Galápagos, Peru, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil North, Brazil South, Argentina Northeast, Argentina South, Argentina Northwest, Chile Central, Chile North, Chile South, Paraguay, Uruguay · introduced: France, Portugal, Sardegna, Spain, Sicilia, Algeria, Egypt, Morocco, Canary Is., Cape Verde, Benin, Burkina, Gambia, The, Ghana, Guinea-Bissau, Guinea, Ivory Coast, Mauritania, Nigeria, Senegal, Sierra Leone, Cameroon, Congo, Gabon, Gulf of Guinea Is., Zaïre, Djibouti, Socotra, Somalia, Sudan, Kenya, Tanzania, Angola, Mozambique, Cape Provinces, Namibia, KwaZulu-Natal, Free State, St.Helena, Aldabra, Chagos Archipelago, Mauritius, Madagascar, Réunion, Seychelles, Gulf States, Oman, Saudi Arabia, Yemen, China South-Central, Hainan, China Southeast, Japan, Nansei-shoto, Taiwan, Bangladesh, India, Laccadive Is., Sri Lanka, Andaman Is., Cambodia, Myanmar, Nicobar Is., South China Sea, Thailand, Vietnam, Cocos (Keeling) I., Jawa, Lesser Sunda Is., Malaya, Maluku, Philippines, Sulawesi, Sumatera, New Guinea, Norfolk Is., New Zealand North, Fiji, Niue, New Caledonia, Samoa, Tokelau-Manihiki, Tonga, Wallis-Futuna Is., Cook Is., Marquesas, Society Is., Tuamotu, Tubuai Is., Caroline Is., 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 marker26.576, -81.915 · in the densest population, 57 records (21% of those in range)
Kew's description“perennial or rhizomatous geophyte” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 273 georeferenced records inside the native range; the climate across the range on the 77 of them in the land cells it reads, of 83 placed to within 10 km; the map shows only the 229 openly licensed ones, which alone would put the marker 13 km away. 1145 records outside the WCVP native range not used. 190 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 273 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Paspalum vaginatum, photograph 1did not loadPaspalum vaginatum, photograph 2did not loadPaspalum vaginatum, photograph 3did not loadPaspalum vaginatum, photograph 4did not loadPaspalum vaginatum, photograph 5did not loadPaspalum vaginatum, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0 (3); (c) Joe Dillon, some rights reserved (CC BY) (2); (c) Tony Rebelo, some rights reserved (CC BY-SA).

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

Clusia rosea Clusia rosea Scotch attorney Photo: CC BY, mbigernaEugenia axillaris Eugenia axillaris White stopper Photo: CC BY, Kristály Cravens-LiszakMyrcia chytraculia Myrcia chytraculia Myrtaceae Photo: CC BY, Rachel StringhamCyperus ligularis Cyperus ligularis Swamp Flatsedge Photo: CC0, author not statedChrysophyllum oliviforme Chrysophyllum oliviforme Satinleaf Photo: CC BY, Martin Hannan-JonesFimbristylis cymosa Fimbristylis cymosa Tropical fimbry Photo: CC BY, Neal Kelso

Other Paspalum 15 in the reference

Paspalum conjugatum Paspalum conjugatum Hilo grass Photo: CC0, author not statedPaspalum dilatatum Paspalum dilatatum Dallis-grass Photo: CC BY, fmunozPaspalum distichum Paspalum distichum Knotgrass Photo: CC BY, Augustin SoulardPaspalum floridanum Paspalum floridanum Florida paspalum Photo: CC BY, Brandon CorderPaspalum laeve Paspalum laeve Field paspalum Photo: CC BY, Bryan ConnollyPaspalum langei Paspalum langei Rusty-seed paspalum Photo: CC0, author not statedPaspalum notatum Paspalum notatum Bahia grass Photo: CC BY, 祐Paspalum paniculatum Paspalum paniculatum Russell River grass Photo: CC BY, GabrielPaspalum plicatulum Paspalum plicatulum Brown-seed paspalum Photo: CC0, author not statedPaspalum pubiflorum Paspalum pubiflorum Hairy-seed paspalum Photo: CC BY, Chris StahlPaspalum quadrifarium Paspalum quadrifarium Tussock paspalum Photo: CC0, author not stated Paspalum racemosum Peruvian paspalum all 16 ›

Names & registers

Also known as Digitaria foliosa; Digitaria paspalodes subsp. longipes; Digitaria paspalodes var. longipes; Digitaria paspaloides var. longipes; Digitaria tristachya and 45 more. (GBIF Backbone)

Under another author Paspalum distichum Duss, 1897 is an older name of this species, not Paspalum distichum, a species of the reference. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Poaceae
Described by
Sw.
Native to
Texas, Alabama, Florida +51
Wild records
273 in range · 229 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; 22 records within 1 km of a botanic garden, herbarium or zoo left out (13 at a botanic garden or arboretum, 3 at a herbarium, 6 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 17.00_-91.250, lapse-corrected +117 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by its label; its IPNI identifier 184742-2 is Kew's for Paspalum vaginatum Sw.
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 224 datasets via GBIF.org; each carries its own licence.

Cultifolio

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