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Senna occidentalis; photograph (c) Aparna, some rights reserved (CC BY) CC BY(c) Aparna, some rights reserved (CC BY) · observed growing wild · 2026-08-31

Senna occidentalis (L.) Link

Septicweed; Coffee senna; Stinking weed; Ant Bush

Fabaceae · Mexico Central, Mexico Northeast +43

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Senna occidentalis, photograph (c) Raja Sekhar Chimirala, some rights reserved (CC BY)Senna occidentalis, photograph (c) Rahul kumar, some rights reserved (CC BY)Senna occidentalis, photograph (c) Aparna, some rights reserved (CC BY)Senna occidentalis, photograph (c) Ian Talty, some rights reserved (CC BY)Senna occidentalis, photograph (c) Ian Talty, some rights reserved (CC BY)Senna occidentalis, photograph (c) Ian Talty, some rights reserved (CC BY) 75 photographs ›
Habitat figures
Cold floor (1 night in 100)
14.4°C
Record low 6.4 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
30°C
May, Jun and Aug at the habitat CHELSA
Rain a year (median across the range)
1,217mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
29–41DLI
Lowest to highest month (DLI) CHELSA
The year in the habitat's months, not shifted
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
A sharp rainy season, May to October (the habitat's months, not shifted), in a year of even temperature. rain rule, CHELSA
Not shifted: the shift rule does not apply to this habitat. The chart is in the habitat's months.

Summary

Senna occidentalis, commonly known as coffee senna, styptic weed, or septicweed, is a species of flowering plant in the family Fabaceae and is native to the southern United States of America, Mexico and South America. It is a shrub with pinnate leaves, with three to seven pairs of broadly elliptic to egg-shaped leaflets, and yellow flowers arranged in groups of two to four, with six fertile stamens in each flower. It is an aggressive, pantropical weed.

Quoted from Wikipedia, "Senna occidentalis", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a sharp season: 70% of the median year's rain (853 mm of 1,112 mm) falls in May to October. The temperature curve is flat, 3.5 °C between the warmest and coldest month, so the growing-season rule does not infer a growing season from it. Months are the habitat's, northern hemisphere. The temperature curve moves under 4 °C between the warmest and coldest month, where the shift rule does not apply, so they are not shifted for a collection elsewhere.

Rain

1,112 mm in the median year at the habitat, 853 mm of it May to October. Wettest month September at 185 mm, driest month March at 32 mm. Across the grid cells of the range the year's total runs 758 mm to 2,181 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,217 mm, is the year's rain at the top of the page; the 1,112 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: 29 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 20, 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 14.4 °C, the absolute minimum 6.4 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 40.0 °C. Monthly means: the coldest month's mean nightly low 19.0 °C in January (across the grid cells of the range 11.5 °C to 23.2 °C), the warmest month's mean daily high 29.9 °C in May (median year across the grid cells of the range, CHELSA). Cold floor: 14.4 °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: 60 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 -56 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 Senna occidentalis through the yearWarmest months May, June and August, mean daily high 30 °C; coldest month January, mean nightly low 19.0 °C; 1,112 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.0°10°20°30°40°50°40.0° 99th-percentile day, NASA POWER6.4° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400mm rainDLI 29–41RH 60–65%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 199 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 / 23–3128 / 24–3129 / 25–3329 / 25–3430 / 23–3530 / 23–3429 / 22–3330 / 23–3329 / 23–3229 / 24–3128 / 24–3027 / 23–30
Night °C19 / 12–2320 / 12–2321 / 14–2422 / 15–2422 / 15–2523 / 15–2523 / 14–2623 / 15–2523 / 16–2522 / 15–2421 / 14–2420 / 12–24
Rain mm40 / 14–20533 / 9–17932 / 4–18845 / 3–18879 / 7–189141 / 27–264160 / 34–311170 / 33–288185 / 44–319118 / 42–27060 / 13–18949 / 8–178
DLI30 / 24–3935 / 29–3937 / 32–4441 / 27–4841 / 22–4937 / 20–4337 / 22–4236 / 28–4133 / 30–3833 / 28–3731 / 25–3929 / 23–39
RH %61 / 53–6860 / 52–6760 / 50–6760 / 49–6761 / 50–6863 / 56–6964 / 57–6864 / 56–6965 / 57–7064 / 56–6962 / 54–6861 / 53–69
How this section is made
Each figure is the median across the 199 grid cells on land that hold in-range records (219 records in those cells; 3 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 1415:1672 (19.225, -96.375). Over 44 years there: absolute minimum 6.4 °C, 1st-percentile night 14.4 °C, 99th-percentile day 40.0 °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 199 distinct grid cells holding 219 of the 222 in-range records (3 further cells with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1415:1672 (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 19.00_-96.250, lapse-corrected -56 m at 6.5 °C/km. Elevation: ETOPO 2022, 28 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, El Salvador, Guatemala, Honduras, Nicaragua, Panama, Aruba, Bahamas, Cayman Is., Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is. AB Ant, Netherlands Antilles, Puerto Rico, Southwest Caribbean, Trinidad-Tobago, Venezuelan Antilles, 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 Northwest, Paraguay, Uruguay · introduced: Egypt, Libya, Canary Is., Cape Verde, Benin, Burkina, Gambia, The, Ghana, Guinea-Bissau, Guinea, Ivory Coast, Liberia, Mali, Mauritania, Nigeria, Niger, Senegal, Sierra Leone, Togo, Burundi, Central African Republic, Cameroon, Congo, Equatorial Guinea, Gabon, Gulf of Guinea Is., Rwanda, Zaïre, Chad, Djibouti, Eritrea, Ethiopia, Somalia, Sudan, Kenya, Tanzania, Uganda, Angola, Malawi, Mozambique, Zambia, Zimbabwe, Botswana, Caprivi Strip, Namibia, KwaZulu-Natal, Swaziland, Northern Provinces, Ascension, St.Helena, Aldabra, Chagos Archipelago, Comoros, Mauritius, Madagascar, Réunion, Rodrigues, Seychelles, Primorye, Iraq, Saudi Arabia, Yemen, China South-Central, China Southeast, Korea, Kazan-retto, Ogasawara-shoto, Assam, Bangladesh, East Himalaya, India, Laccadive Is., Maldives, Nepal, Pakistan, Sri Lanka, West Himalaya, Andaman Is., Cambodia, Laos, Myanmar, Nicobar Is., South China Sea, Thailand, Vietnam, Borneo, Cocos (Keeling) I., Jawa, Lesser Sunda Is., Malaya, Maluku, Philippines, Sulawesi, Sumatera, Christmas I., Bismarck Archipelago, New Guinea, Solomon Is., New South Wales, Northern Territory, Queensland, South Australia, Western Australia, Fiji, Gilbert Is., Nauru, Niue, New Caledonia, Samoa, Tokelau-Manihiki, Tonga, Vanuatu, Cook Is., Line Is., Marquesas, Society Is., Tuamotu, Caroline Is., Marianas, Marshall Is., Hawaii, Illinois, Iowa, Kansas, Missouri, Oklahoma, Indiana, Massachusetts, New York, Texas, Alabama, Arkansas, Florida, Georgia, Louisiana, Maryland, Mississippi, North Carolina, South Carolina, Tennessee, Virginia, Bermuda · 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 marker19.339, -96.49 · in the densest population, 143 records (26% of those in range)
Kew's description“annual, 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 558 georeferenced records inside the native range; the climate across the range on the 219 of them in the land cells it reads, of 222 placed to within 10 km; the map shows only the 435 openly licensed ones, which alone would put the marker 11 km away. 1062 records outside the WCVP native range not used. 336 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 558 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Senna occidentalis, photograph 1did not loadSenna occidentalis, photograph 2did not loadSenna occidentalis, photograph 3did not loadSenna occidentalis, photograph 4did not loadSenna occidentalis, photograph 5did not loadSenna occidentalis, photograph 6did not load

Photographs: (c) Raja Sekhar Chimirala, some rights reserved (CC BY); (c) Rahul kumar, some rights reserved (CC BY); (c) Aparna, some rights reserved (CC BY); (c) Ian Talty, some rights reserved (CC BY) (3).

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

Guazuma ulmifolia Guazuma ulmifolia Bastard-cedar Photo: CC BY, Abby DarrahAmaranthus spinosus Amaranthus spinosus Spiny amaranth Photo: CC0, author not statedIpomoea carnea Ipomoea carnea Gloria de la manana Photo: CC BY, Zac PetersonDesmodium tortuosum Desmodium tortuosum Dixie ticktrefoil Photo: CC BY, Yu-Huang WangPriva lappulacea Priva lappulacea Cat's tongue Photo: CC BY, Francisco Emilio Roldán VelascoDalechampia scandens Dalechampia scandens Spurgecreeper Photo: CC BY, Raúl A. Ruiz M.

Other Senna 68 in the reference

Senna acclinis Senna acclinis Rainforest Cassia Photo: CC BY-SA, Greg TasneySenna aciphylla Senna aciphylla Sprawling Cassia Photo: CC BY, Guy TaseskiSenna alata Senna alata Emperor's candlesticks Photo: CC BY, renjus boxSenna alexandrina Senna alexandrina Alexandrian senna Photo: CC BY, Karim HaddadSenna aphylla Senna aphylla Fabaceae Photo: CC BY, Guillermo DebandiSenna armata Senna armata Desert senna Photo: CC BY, Jacob SaucierSenna arnottiana Senna arnottiana Fabaceae Photo: CC BY, Morten RossSenna artemisioides Senna artemisioides Silver senna Photo: CC BY, Michelle W. （鍾偉瑋）Senna atomaria Senna atomaria Flor de San Jose Photo: CC BY, Jose Luis Leon de la LuzSenna auriculata Senna auriculata Matara-tea Photo: CC BY, Rohit NaniwadekarSenna aymara Senna aymara Fabaceae Photo: CC BY, Thomaz Ricardo Favreto SinaniSenna bacillaris Senna bacillaris Whitebark senna Photo: CC BY, scaup all 69 ›

Names & registers

Also known as Cassia caroliniana; Cassia ciliata; Cassia falcata; Cassia foetida; Cassia glaucescens and 20 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Fabaceae
Described by
(L.) Link
Native to
Mexico Central, Mexico Northeast, Mexico Gulf +42
Wild records
558 in range · 435 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; 30 records within 1 km of a botanic garden, herbarium or zoo left out (19 at a botanic garden or arboretum, 6 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 19.00_-96.250, lapse-corrected -56 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 245 datasets via GBIF.org; each carries its own licence.

Cultifolio

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