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Chamaecrista rotundifolia; photograph (c) geosesarma, some rights reserved (CC BY) CC BY(c) geosesarma, some rights reserved (CC BY) · observed growing wild · 2026-08-25

Chamaecrista rotundifolia (Pers.) Greene

Roundleaf sensitive pea; Round-leaf cassia

Fabaceae · Mexico Central, Mexico Northeast +25

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Chamaecrista rotundifolia, photograph (c) geosesarma, some rights reserved (CC BY)Chamaecrista rotundifolia, photograph (c) Nicolas Olejnik, some rights reserved (CC BY)Chamaecrista rotundifolia, photograph (c) Nicolas Olejnik, some rights reserved (CC BY)Chamaecrista rotundifolia, photograph (c) Giovanna Roque de Castro, some rights reserved (CC BY-SA)Chamaecrista rotundifolia, photograph (c) Giovanna Roque de Castro, some rights reserved (CC BY-SA)Chamaecrista rotundifolia, photograph (c) Giovanna Roque de Castro, some rights reserved (CC BY-SA) 124 photographs ›
Habitat figures
Cold floor (1 night in 100)
12.4°C
Record low 8.1 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
30°C
Apr and May at the habitat CHELSA
Rain a year (median across the range)
1,190mm
8 months of 25 mm or more in the median year CHELSA
Open-sky light
31–47DLI
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 December to March (June to September 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

Chamaecrista rotundifolia, the round-leaf cassia, also known as pasto rastiero, roundleaf sensitive pea, and Wynn cassia, is a short-lived perennial or self-generating annual plant in the subfamily Caesalpinioideae of the family Fabaceae. It originated in North America, Mesoamerica, the Caribbean, and Tropical South America but is grown in other parts of the world today.

Quoted from Wikipedia, "Chamaecrista rotundifolia", CC BY-SA 4.0.

About the genus · Chamaecrista

Chamaecrista is a genus of flowering plants in the pea family, Fabaceae, subfamily Caesalpinioideae. Members of the genus are commonly known as sensitive pea. Several species are capable of rapid plant movement. More on Wikipedia ›

Quoted from Wikipedia, "Chamaecrista", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (863 mm of 1,145 mm) falls in June to September, warmer than the year (wet-season mean 24.0 °C against a yearly mean of 23.1 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: December to March.

Rain

1,145 mm in the median year at the habitat, 863 mm of it June to September. Wettest month July at 242 mm, driest month March at 11 mm. Across the grid cells of the range the year's total runs 801 mm to 2,285 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,190 mm, is the year's rain at the top of the page; the 1,145 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: 31 to 47 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 26, the highest 90th-percentile month 49).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 12.4 °C, the absolute minimum 8.1 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 38.7 °C. Monthly means: the coldest month's mean nightly low 15.5 °C in January (across the grid cells of the range 7.7 °C to 23.0 °C), the warmest month's mean daily high 30.0 °C in May (median year across the grid cells of the range, CHELSA). Cold floor: 12.4 °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: 54 to 66% 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 +108 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 Chamaecrista rotundifolia through the yearWarmest months April and May, mean daily high 30 °C; coldest month January, mean nightly low 15.5 °C; 1,145 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.0°10°20°30°40°38.7° 99th-percentile day, NASA POWER8.1° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 31–47RH 54–66%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 82 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 °C27 / 22–3127 / 24–3129 / 26–3130 / 27–3230 / 27–3329 / 26–3128 / 25–3128 / 25–3127 / 24–3128 / 24–3128 / 24–3027 / 23–30
Night °C16 / 8–2316 / 8–2316 / 10–2417 / 12–2319 / 14–2420 / 15–2420 / 15–2520 / 15–2520 / 15–2519 / 14–2418 / 10–2416 / 9–24
Rain mm34 / 11–11918 / 8–16411 / 3–24717 / 2–23650 / 14–294182 / 47–379242 / 37–406229 / 57–384210 / 38–354104 / 24–24528 / 10–19220 / 6–148
DLI32 / 28–3738 / 33–3943 / 34–4547 / 30–4946 / 28–4937 / 26–4235 / 28–4036 / 31–4034 / 30–3834 / 31–3933 / 29–3931 / 27–38
RH %54 / 49–6454 / 48–6355 / 45–6454 / 44–6556 / 46–6863 / 56–6964 / 59–6965 / 59–6966 / 59–7063 / 56–6758 / 51–6655 / 50–64

Records on both sides of the equator: the 55 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 82 cells that remain: the 59 at least 10° north and the 23 within 10° of the equator, which stay in either way.

How this section is made
Each figure is the median across the 82 grid cells on land that hold in-range records (104 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 1434:1574 (18.275, -101.275). Over 44 years there: absolute minimum 8.1 °C, 1st-percentile night 12.4 °C, 99th-percentile day 38.7 °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 82 distinct grid cells holding 104 of the 168 in-range records (1 further cell with records at sea, by the elevation layer, left out) on the northern side of the equator (59 cells poleward of 10° north, 55 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 1434:1574 (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 18.50_-101.250, lapse-corrected +108 m at 6.5 °C/km. Elevation: ETOPO 2022, 903 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 Northwest, Mexico Southwest, Mexico Southeast, Belize, Costa Rica, Honduras, Nicaragua, Panama, Cuba, Jamaica, Puerto Rico, Guyana, Venezuela, Bolivia, Colombia, Ecuador, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil North, Brazil South, Argentina Northeast, Paraguay, Uruguay · introduced: Benin, Gambia, The, Ghana, Nigeria, Togo, Gabon, Zimbabwe, India, Myanmar, Norfolk Is., New South Wales, Northern Territory, Queensland, Western Australia, Florida · 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-13.463, -41.829 · in the densest population, 323 records (38% of those in range)
Kew's description“perennial or subshrub” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 853 georeferenced records inside the native range; the climate across the range on the 104 of them in the land cells it reads, of 168 placed to within 10 km; the map shows only the 764 openly licensed ones, which alone would put the marker 18 km away. 788 records outside the WCVP native range not used. 685 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 853 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Chamaecrista rotundifolia, photograph 1did not loadChamaecrista rotundifolia, photograph 2did not loadChamaecrista rotundifolia, photograph 3did not loadChamaecrista rotundifolia, photograph 4did not loadChamaecrista rotundifolia, photograph 5did not loadChamaecrista rotundifolia, photograph 6did not load

Photographs: (c) geosesarma, some rights reserved (CC BY); (c) Nicolas Olejnik, some rights reserved (CC BY) (2); (c) Giovanna Roque de Castro, some rights reserved (CC BY-SA) (3).

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

Barleria oenotheroides Barleria oenotheroides Acanthaceae Photo: CC BY, Oscar Israel Rodríguez OrtizBillbergia pallidiflora Billbergia pallidiflora Bromeliaceae Photo: CC BY, José Javier Barrios FloresArdisia revoluta Ardisia revoluta Primulaceae Photo: CC BY, Ricardo Betancourt SánchezMelampodium divaricatum Melampodium divaricatum Gold Medallion Photo: CC BY, Silvia TenArachnothryx leucophylla Arachnothryx leucophylla Panama rose Photo: CC BY, Alexis López HernándezPhilodendron warszewiczii Philodendron warszewiczii Araceae Photo: CC0, author not stated

Other Chamaecrista 11 in the reference

Chamaecrista absus Chamaecrista absus Tropical sensitive pea Photo: CC BY, Robert TaylorChamaecrista desvauxii Chamaecrista desvauxii Fabaceae Photo: CC BY, Connor Connolly-MoylsChamaecrista ensiformis Chamaecrista ensiformis Fabaceae Photo: CC BY, Diogo LuizChamaecrista fasciculata Chamaecrista fasciculata Showy partridge-pea Photo: CC BY, Paul RootsChamaecrista garambiensis Chamaecrista garambiensis Fabaceae Photo: CC BY, Min-Hsuan NIChamaecrista glandulosa Chamaecrista glandulosa Jamaican broom Photo: CC BY-SA, Oscar C. González MartínezChamaecrista greggii Chamaecrista greggii Gregg's sensitive pea Photo: CC BY, Cody HinchliffChamaecrista mimosoides Chamaecrista mimosoides Japanese-tea Photo: CC BY, Hildegard KleinChamaecrista nictitans Chamaecrista nictitans Sensitive partridge pea Photo: CC0, author not statedChamaecrista nomame Chamaecrista nomame Field sensitive pea Photo: CC BY, WATANABE Hitoshi 渡辺仁Chamaecrista serpens Chamaecrista serpens Slender sensitive pea Photo: CC BY, Daniel McNair

Names & registers

Also known as Cassia bifoliata; Cassia bifoliola; Cassia bifoliolata var. rotundifolia; Cassia rotundifolia; Cassia tenuivenosa. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Fabaceae
Described by
(Pers.) Greene
Native to
Mexico Central, Mexico Northeast, Mexico Gulf +24
Wild records
853 in range · 764 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 2026-10-21
GBIF species record gbif.species answeredasked 2026-10-21
GBIF synonyms gbif.synonyms answeredasked 2026-10-21
GBIF common names gbif.vernacular answeredasked 2026-10-21names fetched 2026-10-21
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 (5 at a botanic garden or arboretum, 8 at a herbarium, 9 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-21
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-21NASA POWER (MERRA-2) daily 1981–2024, cell 18.50_-101.250, lapse-corrected +108 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-21
Wikipedia wikipedia answeredasked 2026-10-21
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 2026-10-21
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 177 datasets via GBIF.org; each carries its own licence.

Cultifolio

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