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Cyclospermum leptophyllum; photograph author not stated, no rights reserved CC0author not stated, no rights reserved · observed growing wild · 2026-09-10

Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P.Wilson

Apiaceae · Mexico Central, Mexico Northeast +26

Cited as Kew's World Checklist cites it, Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P.Wilson: GBIF's backbone key for this page carries the name with another author, (Pers.) Sprague.

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Cyclospermum leptophyllum, photograph author not stated, no rights reservedCyclospermum leptophyllum, photograph author not stated, no rights reservedCyclospermum leptophyllum, photograph author not stated, no rights reservedCyclospermum leptophyllum, photograph author not stated, no rights reservedCyclospermum leptophyllum, photograph author not stated, no rights reservedCyclospermum leptophyllum, photograph (c) Sam Kieschnick, some rights reserved (CC BY) 91 photographs ›
Habitat figures
Cold floor (1 night in 100)
2.3°C
Record low -2.1 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
29°C
May at the habitat CHELSA
Rain a year (median across the range)
910mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
26–40DLI
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 November to April (May to October 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

Cyclospermum leptophyllum (also, Ciclospermum l.) is a species of plant in the family Apiaceae known by the common names marsh parsley, slender celery and fir-leaved celery. This is a plant found worldwide at warm temperate to tropical latitudes and is considered a noxious weed in many areas. It is a taprooted branching herb reaching just over half a meter in height at maximum. It has threadlike green leaves a few centimeters long and small umbels of spherical flowers. More on Wikipedia ›

Quoted from Wikipedia, "Cyclospermum leptophyllum", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (705 mm of 945 mm) falls in May to October, warmer than the year (wet-season mean 21.9 °C against a yearly mean of 18.9 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: November to April.

Rain

945 mm in the median year at the habitat, 705 mm of it May to October. Wettest month June at 133 mm, driest month February at 32 mm. Across the grid cells of the range the year's total runs 581 mm to 1,911 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 910 mm, is the year's rain at the top of the page; the 945 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: 26 to 40 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 48).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 2.3 °C, the absolute minimum -2.1 °C, 26 frost nights in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 28.9 °C. Monthly means: the coldest month's mean nightly low 7.9 °C in January (across the grid cells of the range 4.9 °C to 14.8 °C), the warmest month's mean daily high 28.7 °C in May (median year across the grid cells of the range, CHELSA). Cold floor: 2.3 °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: 57 to 62% 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 +785 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 Cyclospermum leptophyllum through the yearWarmest month May, mean daily high 29 °C; coldest month January, mean nightly low 7.9 °C; 945 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.-10°0°10°20°30°40°frost28.9° 99th-percentile day, NASA POWER-2.1° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400mm rainDLI 26–40RH 57–62%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 125 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 °C20 / 16–2421 / 18–2624 / 22–2827 / 23–3029 / 23–3228 / 21–3326 / 20–3426 / 20–3525 / 20–3225 / 19–2722 / 19–2520 / 16–24
Night °C8 / 5–158 / 6–1511 / 8–1615 / 10–1817 / 11–2018 / 12–2317 / 11–2417 / 11–2517 / 11–2215 / 10–1811 / 8–178 / 6–16
Rain mm34 / 10–6632 / 8–6335 / 5–7450 / 10–8086 / 28–160133 / 72–337130 / 54–296122 / 51–301132 / 73–361102 / 41–20753 / 10–10636 / 6–70
DLI27 / 19–3333 / 23–3838 / 29–4540 / 35–4840 / 37–4740 / 33–4240 / 33–4340 / 34–4134 / 30–3630 / 26–3528 / 20–3326 / 17–32
RH %58 / 50–6558 / 48–6457 / 45–6357 / 44–6460 / 47–6760 / 56–6962 / 56–6862 / 55–6862 / 56–7160 / 56–7058 / 52–6858 / 51–67

Records on both sides of the equator: the 82 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 125 cells that remain: the 118 at least 10° north and the 7 within 10° of the equator, which stay in either way.

How this section is made
Each figure is the median across the 125 grid cells on land that hold in-range records (145 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 1462:1745 (16.875, -92.725). Over 44 years there: absolute minimum -2.1 °C, 1st-percentile night 2.3 °C, 99th-percentile day 28.9 °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 125 distinct grid cells holding 145 of the 229 in-range records (1 further cell with records at sea, by the elevation layer, left out) on the northern side of the equator (118 cells poleward of 10° north, 82 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 1462:1745 (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_-92.500, lapse-corrected +785 m at 6.5 °C/km. Elevation: ETOPO 2022, 2054 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.
NativeMexico Central, Mexico Northeast, Mexico Gulf, Mexico Southwest, Mexico Southeast, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil South, Argentina Northeast, Argentina South, Argentina Northwest, Chile Central, Chile North, Chile South, Paraguay, Uruguay · introduced: Great Britain, Belgium, Czechoslovakia, Germany, Corse, France, Portugal, Sardegna, Spain, Albania, Greece, Italy, Egypt, Libya, Azores, Canary Is., Cape Verde, Madeira, Niger, Gulf of Guinea Is., Ethiopia, Kenya, Tanzania, Uganda, Angola, Mozambique, Zambia, Zimbabwe, Botswana, Cape Provinces, Lesotho, Namibia, KwaZulu-Natal, Free State, Swaziland, Northern Provinces, Mauritius, Madagascar, Réunion, Rodrigues, Transcaucasus, Iran, Palestine, Turkey, China South-Central, Hainan, China North-Central, China Southeast, Japan, Korea, Nansei-shoto, Taiwan, India, Nepal, Pakistan, Sri Lanka, West Himalaya, Myanmar, Jawa, Philippines, New Guinea, Norfolk Is., New South Wales, Northern Territory, Queensland, South Australia, Tasmania, Victoria, Western Australia, New Zealand North, New Zealand South, Fiji, Niue, New Caledonia, Tonga, Vanuatu, Cook Is., Easter Is., Pitcairn Is., Tubuai Is., Hawaii, Oregon, Illinois, Missouri, Oklahoma, New York, Ohio, Pennsylvania, West Virginia, Arizona, California, Nevada, New Mexico, Texas, Alabama, Arkansas, Florida, Georgia, Louisiana, Maryland, North Carolina, South Carolina, Tennessee, Virginia, Mexico Northwest, Bermuda, Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is. AB Ant, Puerto Rico, Windward Is., Galápagos, Juan Fernández Is. · 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-34.834, -55.156 · in the densest population, 119 records (29% of those in range)
Kew's description“annual” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 417 georeferenced records inside the native range; the climate across the range on the 145 of them in the land cells it reads, of 229 placed to within 10 km; the map shows only the 281 openly licensed ones, which alone would put the marker 846 km away. 778 records outside the WCVP native range not used. 188 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 417 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Cyclospermum leptophyllum, photograph 1did not loadCyclospermum leptophyllum, photograph 2did not loadCyclospermum leptophyllum, photograph 3did not loadCyclospermum leptophyllum, photograph 4did not loadCyclospermum leptophyllum, photograph 5did not loadCyclospermum leptophyllum, photograph 6did not load

Photographs: author not stated, no rights reserved · CC0 (5); (c) Sam Kieschnick, some rights reserved (CC BY).

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

Quercus polymorpha Quercus polymorpha Netleaf white oak Photo: CC BY, Neptalí Ramírez MarcialQuercus rysophylla Quercus rysophylla Loquat leaf oak Photo: CC BY, Cody HinchliffBeschorneria septentrionalis Beschorneria septentrionalis Asparagaceae Photo: CC BY, Claudio Cantú Muñiz Brahea moorei Arecaceae Eleocharis montana Eleocharis montana Mountain spikerush Photo: CC BY, Sue CarnahanSedum calcicola Sedum calcicola Crassulaceae Photo: CC BY-SA, Rogelio Reyna-Hernández

Names & registers

Also known as Aethusa leptophylla; Apium ammi; Apium ammi f. filamentosum; Apium ammi f. nanum; Apium ammi f. pedunculatum and 38 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Apiaceae
Described by
(Pers.) Sprague ex Britton & P.Wilson
Native to
Mexico Central, Mexico Northeast, Mexico Gulf +25
Wild records
417 in range · 281 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 2026-10-22GBIF's key 8350395 is Cyclospermum leptophyllum (Pers.) Sprague; the page links Kew's Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P.Wilson, and the name is cited as Kew cites it
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; 81 records within 1 km of a botanic garden, herbarium or zoo left out (55 at a botanic garden or arboretum, 13 at a herbarium, 13 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_-92.500, lapse-corrected +785 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22IPNI and POWO linked by Kew's number for Cyclospermum leptophyllum (Pers.) Sprague ex Britton & P.Wilson (the item's: IPNI 1214728-2, POWO 840899-1)
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 191 datasets via GBIF.org; each carries its own licence.

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