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Rhynchospora corymbosa; photograph (c) Scott W. Gavins, some rights reserved (CC BY) CC BY(c) Scott W. Gavins, some rights reserved (CC BY) · observed growing wild · 2026-08-18

Rhynchospora corymbosa (L.) Britton

Matamat; Golden beak sedge

Cyperaceae · Benin, Burkina +109

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Rhynchospora corymbosa, photograph (c) Scott W. Gavins, some rights reserved (CC BY)Rhynchospora corymbosa, photograph (c) Mark Clarke, some rights reserved (CC BY)Rhynchospora corymbosa, photograph (c) Mark Clarke, some rights reserved (CC BY)Rhynchospora corymbosa, photograph (c) Mark Clarke, some rights reserved (CC BY)Rhynchospora corymbosa, photograph (c) Mark Clarke, some rights reserved (CC BY)Rhynchospora corymbosa, photograph (c) Mark Clarke, some rights reserved (CC BY) 73 photographs ›
Habitat figures
Cold floor (1 night in 100)
15.3°C
Record low 13.4 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
28°C
Jan, Feb, Mar, Nov and Dec at the habitat CHELSA
Rain a year (median across the range)
1,688mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
25–39DLI
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
Wet summers: the rain comes May to November (November to May at the habitat), read as a summer growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Rhynchospora corymbosa, known by the common names of golden beaksedge and matamat, is a member of the sedge family, Cyperaceae. It is a perennial herb, found globally throughout the tropics. It grows up to 2 meters tall in riverbanks, shallow pools, and swamps.

Quoted from Wikipedia, "Rhynchospora corymbosa", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (1,143 mm of 1,576 mm) falls in November to May, warmer than the year (wet-season mean 24.9 °C against a yearly mean of 23.6 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: May to November.

Rain

1,576 mm in the median year at the habitat, 1,143 mm of it November to May. Wettest month February at 191 mm, driest month August at 66 mm. Across the grid cells of the range the year's total runs 1,097 mm to 3,202 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,688 mm, is the year's rain at the top of the page; the 1,576 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, southern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 25 to 39 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 19, the highest 90th-percentile month 43).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 15.3 °C, the absolute minimum 13.4 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 26.4 °C. Monthly means: the coldest month's mean nightly low 17.6 °C in July (across the grid cells of the range 10.7 °C to 23.8 °C), the warmest month's mean daily high 28.3 °C in January and February (median year across the grid cells of the range, CHELSA). Cold floor: 15.3 °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: 63 to 65% 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 +605 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, southern hemisphere

Habitat climate of Rhynchospora corymbosa through the yearWarmest months January, February, March, November and December, mean daily high 28 °C; coldest month July, mean nightly low 17.6 °C; 1,576 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, southern hemisphere.5°10°15°20°25°30°35°26.4° 99th-percentile day, NASA POWER13.4° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 25–39RH 63–65%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 227 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 °C28 / 26–3228 / 26–3328 / 25–3226 / 23–3125 / 21–3023 / 19–2923 / 19–2924 / 20–3025 / 22–3027 / 23–3028 / 24–3128 / 26–32
Night °C23 / 20–2523 / 20–2523 / 19–2522 / 17–2520 / 15–2518 / 12–2418 / 11–2418 / 11–2419 / 14–2421 / 16–2422 / 18–2522 / 19–25
Rain mm157 / 13–453191 / 31–461177 / 79–418172 / 89–340149 / 65–333111 / 45–32477 / 34–27566 / 30–24372 / 38–288107 / 56–327128 / 47–287169 / 20–320
DLI37 / 31–4235 / 33–3833 / 32–3630 / 27–3527 / 21–3225 / 19–3125 / 21–3328 / 24–3534 / 27–3937 / 28–4339 / 29–4338 / 29–43
RH %63 / 59–6964 / 60–6964 / 60–6965 / 60–7065 / 59–7065 / 57–7064 / 55–6964 / 55–6963 / 56–7063 / 57–7064 / 59–6964 / 60–68

Records on both sides of the equator: the 59 cells at least 10° north of it have seasons six months apart and are left out, not combined into a year no place has. These figures are across the 227 cells that remain: the 137 at least 10° south and the 90 within 10° of the equator, which stay in either way.

How this section is made
Each figure is the median across the 227 grid cells on land that hold in-range records (281 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 1766:3805 (1.675, 10.275). Over 44 years there: absolute minimum 13.4 °C, 1st-percentile night 15.3 °C, 99th-percentile day 26.4 °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 227 distinct grid cells holding 281 of the 354 in-range records (1 further cell with records at sea, by the elevation layer, left out) on the southern side of the equator (59 cells poleward of 10° north, 137 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 1766:3805 (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 1.50_10.000, lapse-corrected +605 m at 6.5 °C/km. Elevation: ETOPO 2022, 898 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.
NativeBenin, Burkina, The Gambia, Ghana, Guinea-Bissau, Guinea, Ivory Coast, Liberia, Mali, Mauritania, Nigeria, Senegal, Sierra Leone, Togo, Burundi, Central African Republic, Cameroon, Congo, Equatorial Guinea, Gabon, Gulf of Guinea Is., Zaïre, Chad, Ethiopia, Sudan, Tanzania, Uganda, Angola, Malawi, Mozambique, Zambia, Zimbabwe, Botswana, Cape Provinces, KwaZulu-Natal, Mauritius, Madagascar, China South-Central, Hainan, China Southeast, Nansei-shoto, Taiwan, Assam, Bangladesh, East Himalaya, India, Sri Lanka, Andaman Is., Cambodia, Myanmar, Nicobar Is., Thailand, Vietnam, Borneo, Jawa, Lesser Sunda Is., Malaya, Maluku, Philippines, Sulawesi, Sumatera, Bismarck Archipelago, New Guinea, New South Wales, Northern Territory, Queensland, Fiji, Samoa, Tonga, Vanuatu, Wallis-Futuna Is., Society Is., Tubuai Is., Caroline Is., Marianas, Mexico Central, Mexico Gulf, Mexico Southwest, Mexico Southeast, Belize, Costa Rica, Guatemala, Honduras, Nicaragua, Panama, Cuba, Dominican Republic, 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, Paraguay, Uruguay · 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 marker-25.9, -57.15 · in the densest population, 259 records (18% 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 1420 georeferenced records inside the native range; the climate across the range on the 281 of them in the land cells it reads, of 354 placed to within 10 km; the map shows only the 1227 openly licensed ones, which alone would put the marker 10 km away. 34 records outside the WCVP native range not used. 1066 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 1420 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Rhynchospora corymbosa, photograph 1did not loadRhynchospora corymbosa, photograph 2did not loadRhynchospora corymbosa, photograph 3did not loadRhynchospora corymbosa, photograph 4did not loadRhynchospora corymbosa, photograph 5did not loadRhynchospora corymbosa, photograph 6did not load

Photographs: (c) Scott W. Gavins, some rights reserved (CC BY); (c) Mark Clarke, some rights reserved (CC BY) (5).

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

Eugenia astringens Eugenia astringens Myrtaceae Photo: CC BY, Diogo LuizPhilodendron bipennifolium Philodendron bipennifolium Fiddle-leaf philodendron Photo: CC0, author not statedAvicennia schaueriana Avicennia schaueriana Acanthaceae Photo: CC BY-SA, lucas_rafaelleGoeppertia cylindrica Goeppertia cylindrica Marantaceae Photo: CC BY, Victor Farjalla PontesAegiceras corniculatum Aegiceras corniculatum Black mangrove Photo: CC BY, James HCyrtopodium flavum Cyrtopodium flavum Yellow Cowhorn Orchid Photo: CC0, author not stated

Other Rhynchospora 9 in the reference

Rhynchospora alba Rhynchospora alba White beak-sedge Photo: CC BY, Мирослав СоболевRhynchospora capitellata Rhynchospora capitellata Brownish beaksedge Photo: CC BY, John BaurRhynchospora colorata Rhynchospora colorata Starrush whitetop Photo: CC0, author not statedRhynchospora corniculata Rhynchospora corniculata Short-bristle hornedrush Photo: CC BY, Ryan SorrellsRhynchospora latifolia Rhynchospora latifolia Giant Whitetop Photo: CC0, author not stated Rhynchospora macrochaeta Cyperaceae Rhynchospora modesti-lucennoi Rhynchospora modesti-lucennoi Cyperaceae Photo: CC BY, Duarte FradeRhynchospora nervosa Rhynchospora nervosa Yerba de estrella Photo: CC BY, Arthur BruckRhynchospora pura Rhynchospora pura Cyperaceae Photo: CC BY, Karen Saunders

Names & registers

Also known as Calyptrostylis articulata; Calyptrostylis asperula subsp. minor; Calyptrostylis asperula var. minor; Calyptrostylis divergens; Calyptrostylis fascicularis and 53 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Cyperaceae
Described by
(L.) Britton
Native to
Benin, Burkina, The Gambia +108
Wild records
1420 in range · 1227 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; 27 records within 1 km of a botanic garden, herbarium or zoo left out (13 at a botanic garden or arboretum, 7 at a herbarium, 7 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 1.50_10.000, lapse-corrected +605 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
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 227 datasets via GBIF.org; each carries its own licence.

Cultifolio

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